AAT ID Label Note A breccia marble that consists of large pebbles of black, green, pink, red, gray, purple and bronze; it is noted for its strongly pronounced colors. It is from the Greek aat:300011461 Affricano island of Chios and so has nothing to do with Africa; its name is due to its dusky coloration. Term used in the glass trade for a type of art glass first produced by the New England Glass Company in 1886, characterized by a glossy mottled surface created by first aat:300206142 Agata glass coating the object with metallic stain and then spaatering it with a volatile liquid; the finish is fixed by a light firing. aat:300011573 Alabama Cream An American white marble suitable for sculpture. aat:300011313 Alabama limestone A light tan-gray or nearly white oolitic limestone quarried in Colbert County, Alabama that contains large isolated shells and other fossils. Clay used by potters to produce a natural black or brown glaze on stoneware. It is found near Albany, New York, and is frequently used on salt-glazed stoneware from aat:300010460 Albany slip clay the early 19th century onwards. A bluish gray stone quarried in Virginia; commonly used for building trim and for chemical laboratory tables and sinks; hard varieties employed for stair treads and aat:300011666 Alberene stone flooring. Refers to a type of glass produced in the town of Altare, near Genoa, Italy. The glass industry was established there in the 9th century by glassmakers from Normandy or Flanders. The term particularly refers to glass dating from the 15th century and later that was produced here, or that was made elsewhere based on techniques aat:300263808 Altare glass taught by Altare glassmakers. During this period Altare glassmakers imitated the highly sought-after and secret techniques of Venetian glassmakers, and they spread the secrets to other European centers. Term used in the glass trade for uncased art glass developed by the New England Glass Company in 1883, which varies in shading from light amber to deep ruby, the aat:300206163 Amberina glass ruby areas result when part of the glass is reheated and the gold particles in the glass develop a ruby color. A type of glass manufactured by German-American John Frederick Amelung’s New Bremen Glass Manufactory in Maryland, U.S. between 1784 and ca. 1795. Amelung brought over German craftsmen and sought financial support from German and American businessmen and the U.S. government in establishing a permanent crafts aat:300380220 Amelung glass community. His industry failed after the U.S. Congress rejected Amelung’s request for a loan in 1790. Our understanding of the technique and style of this glass is largely speculative and fragmentary as few examples survive. Variable term referring to an imitation vermilion pigment composed of basic lead chromate, or a lake of synthetic red dye, such as eosin or scarlet dye, on a red base, aat:300311449 American vermilion such as red lead, orange mineral, or chrome red. aat:300011410 Amherst sandstone A stone from Ohio, containing up to 95% silica with 4% aluminum oxide, and colored gray and buff with iron oxides. aat:300379837 Angera stone A fine grain dolomitic limestone, yellow, white, or pink in color, quarried along the eastern shore of Lago Maggiore near Angera in the Lombardy region of northern Italy. A brown to light-gray siliceous sandstone from Aquia Creek in Stafford County, Virginia. It contains rounded, coarse to fine grains of quartz as well as scaatered pebbles aat:300011411 Aquia Creek sandstone and clay pellets as big as 1 inch in diameter; it splits easily in any desired direction. Aquia Creek sandstone was one of the important building stones in early Washington, D.C. A fine grained ferruginous sandstone quarried in Arizona that can be buff, brown, or pink in color; it is one of the most common and inexpensive sedimentary stones aat:300011402 Arizona flagstone used as flagstone. It is strong, abrasion resistant, and has a natural non-slip surface, making it an exceptional flooring material. It is colorfast and can be used indoors or outdoors. Soft red ocher that is a natural mixture of hydrated silicate clays colored with red iron oxide. Since at least the 17th century, it has been used as a foundation for gold aat:300311590 Armenian bole leaf and as a red earth pigment. aat:300010982 Ashbury metal A type of pewter that is a very hard alloy of tin with antimony and zinc, sometimes with copper or other materials. Often used for such items as spoons and snuffboxes. Term used in the glass trade for a type of art glass developed at the Steuben Glass Works with either a purplish, bluish, or golden metallic appearance created by aat:300206172 Aurene glass spraying the glass at the fire with stannous chloride or lead chloride under controlled atmospheric conditions. The original trademarked name for phenol-formaldehyde resin, but now used to refer to a range of different types of plastic. The method for manufacturing the original resin was devised in 1909 by L. H. Baekeland in the United States, and the name Bakelite is a registered trademark of the Union Carbide Corporation. It is a hard, aat:300014544 Bakelite (TM) infusible, and chemically resistant plastic, nonconductor of electricity, and used in electrical appliances, industrial applications, in molding and casting operations, as an adhesive, in paints, and in baked-enamel coatings. aat:300011314 Bangor limestone An oolitic limestone, quarried in Alabama, that is highly valued as a building stone. aat:300011361 Barnack stone Oolitic limestone quarried in the vicinity of Barnack, Cambridgeshire, England; used primarily as a building stone. aat:300011199 Barre granite A type of gray granite quarried in Barre, Vermont, a center of granite quarrying in the U.S. since just after the War of 1812. General term referring to various dammar resins that were formerly shipped under the tradename "Batavia" from Jakarta (formerly Batavia), Indonesia. General term aat:300012925 Batavia dammar referring to various dammar resins that were formerly shipped under the tradename "Batavia" from Jakarta (formerly Batavia), Indonesia. aat:300011315 Batesville marble Limestone from Arkansas, gray or cream colored. The general name for oolitic limestone found extensively in southwestern England, particularly near Bath, hence its name. It is medium or fine-grained and its color aat:300011316 Bath stone ranges from gray to cream. Bath stone has been widely used since the Roman occupation of Britain and was especially popular for English ecclesiastical architecture of the thirteenth, fourteenth, and fifteenth centuries. aat:300011302 Beer stone Fine textured white limestone quarried in the vicinity of Beer, Devon, England; used primarily as a building stone. aat:300011485 Belgian black marble A dense, hard marble from Belgium, considered the best black marble for carving due to its deep color and lack of veins and streaks. aat:300011719 Belgian block A type of paving stone generally cut in a slightly pyramidal shape, laid with the base of the pyramid down. aat:300378963 Bombay mastic The resin collected in India. aat:300375602 Bordeaux turpentine The raw balsam of the French Maritime pine tree, Pinus pinaster. It is used to produce the distilled "Burgundy turpentine" and "Burgundy pitch," which is not distilled. aat:300178756 Botticino marble An Italian marble which can either be dark cream, light cream with brown markings, or light brown with whitish patches. Refers to pink or reddish topaz, usually having been produced by exposing yellow Brazilian topaz to moderate heat, causing it to turn pink. The term may also refer to aat:300266269 Brazilian ruby (mineral) the extremely rare naturally occurring pink or red topaz. The non-distilled residue created from the creation of Burgundy turpentine, which is the steam distillation of the balsam from the French Maritime pine tree, Pinus aat:300012896 Burgundy pitch maritinus. Used as a cement and as a coating for bronzes during the Italian Renaissance. Term used in the glass trade for a type of art glass developed by the Mt. Washington Glass Company, shaded from pink to yellow with pink at the top caused by the aat:300206177 Burmese glass presence of gold and uranium. aat:300011318 Caen stone A fine-grained French oolitic limestone that is cream in color and easily carved. A crystal clear, resinous exudate from the Canadian balsam fir, Abies balsamea, native to northeastern North America. Canada balsam was introduced in Europe in the aat:300012897 Canada balsam (resin) 18th century. It was used for as varnish, but was found to bloom in moist conditions and darken with age. It is currently used to permanently mount microscopy specimens and as an adhesive for optical lenses. Its softening point is slightly above room temperature. Coarse grained, veined marble ranging in color from white to salmon-pink, quarried in and around Candoglia, Piedmont, Italy. It is primarily known as the building aat:300379450 Candoglia marble material used for Milan Cathedral. aat:300249587 Carboniferous limestone Limestone from the Carboniferous period from about 345 to 280 million years ago. aat:300400672 Cardiidae (fossils) General denomination for the fossils of certain bivalve molluscs. Distinguished from the family of living cockles comprised of over 200 species. Refers to a type of marble quarried in the area around Carrara, in Tuscany, Italy. It is characterized by a fine, compact grain and varies in color from pure white to aat:300011576 Carrara marble creamy white, sometimes with a bluish tinge; it is a saccharoidal rock that can appear translucent in the finer grades. It has been a favorite stone of sculptors from antiquity to the present, including Michelangelo Buonarotti. Luna marble was the name used in ancient Rome. A type of structural plate glass that is ground to true plane surfaces; used for storefronts, countertops, tiling, and paneling. It is made in many colors in thicknesses from aat:300010856 Carrara structural glass (TM) 11/32 to 1 1/2 inches (0.86 to 3.81 cm) or laminated to give different color effects. A type of hard soap that is mild, odorless, and white or semitransparent, made with olive oil or other vegetable oils and sodium hydroxide or sodium carbonate. Castile aat:300266181 Castile soap soap is used to clean leather (saddle soap) and other items. aat:300011192 China stone (granite) A partially decomposed feldspathic granite found in China and used with clay to make oriental porcelain. Fairly hard, yellowish-white wax composed primarily of ceryl cerotate and other esters, excreted by the louse-like scale insects of the genus Ceroplastes found in China, aat:300014594 Chinese insect wax Japan, and India. The insects deposit their wax onto the leaves and twigs of Chinese ash trees; it is scraped off, cleaned with hot water, and cast into molds. It is similar to spermaceti and has been used as a substitute for beeswax, for candles, wax paint, polishing leather, and sizing paper. aat:300013574 Chinese vermilion Type of dry-process vermilion pigment originally made in China. aat:300378962 Chios mastic The resin collected from the Greek island of Chios, having the reputation for the highest quality. aat:300011304 Clipsham stone Oolitic limestone, quarried in the vicinity of Clipsham, Leicestershire, England; used primarily as a building stone. A type of glass characterized by its mainly greenish, turquoise, yellow, brown-green, or smoky black color accented by air bubbles, streaks of pink and white, and speckles of aventurine. To produce Clutha glassware, a worker used a gather of pale ruby or pale yellow glass, then rolled it over a marver lightly sprinkled with bits of aat:300206370 Clutha glass colored glass and mica flakes. The gather was reheated and blown and tooled into the finished product. It was originally made by James Couper & Sons, Glasgow. It is called "Clutha" from Gaelic for "cloudy." A type of art glass characterized by large air bubbles of various sizes combined with larger unsifted glass particles, and cased with heavier clear glass. Cluthra glassware aat:300211737 Cluthra glass is made from a lump of crystal glass on a blowing iron, which is rolled across a marver that had been sprinkled with powdered glass of any desired color. It was developed at Steuben Glass Works before 1930 as a variation on the very similar Clutha glass. aat:300010675 Coade stone Building material, composed of ceramic similar to stoneware, developed in England around 1769, used primarily for architectural decoration. A fine grained, magnesium-rich white marble from Cockeysville, Maryland; it has a few pale streaks or bands which give an effect of pale gray. One of the most popular aat:300011577 Cockeysville marble types of marble used in nineteenth-century buildings in Washington, D.C., it comprised the top two thirds of the Washington Monument as well as the monolithic columns of the Capitol building extensions. A fine-grain marble quarried near Marble in Gunnison County, Colorado. Colorado Yule marble is usually pure white but can have pale gray clouds and/or creamy veins. aat:300011578 Colorado Yule marble Some regions of the marble belt have a pale blue-gray color. Colorado Yule has been used for statuary and was used for the exterior of the Lincoln Memorial. A medium hard variety of copal resin obtained from both living trees and as fossil resin from the genus Copaifera in western Africa. Congo copal is insoluble in most aat:300012912 Congo copal (resin) organic solvents until it has been thermally treated. It forms transparent gels with some alcohols, hot oils and and hot solvents. Congo copal is used in varnishes and paints for metal surfaces. A predominantly pale green marble with white markings that is quarried near Clifden in County Galway, Ireland. A metamorphosed dolomitic limestone, it is considered aat:300011513 Connemara marble to be one of two true marbles native to the British Isles, the other being Iona marble. A weathering steel that has superior corrosion resistance over regular carbon steel because of a protective oxide film on the metal's surface. Its 50,000 minimum yield strength allows for cost reduction because lighter sections can be designed and built into structures; it is generally meant to be used in unpainted applications where a aat:300178799 Cor-Ten steel (TM) reduction in maintenance costs, such as painting, are desired. Cor-Ten is a brand name for corrosion resistant products that were developed by United States Steel; Cor- Ten has subsequently been licensed to be produced by other steel manufacturers. aat:300211572 Coralene glass Glass decorated with coral-like sprays created with enamel and applied glass beads fused to the object. A patinated alloy of copper with varying amounts of gold and silver, said to have been developed in Corinth in the second century BCE, and highly valued for ornament aat:300263090 Corinthian bronze and statues. Objects cast from the metal were subjected to a heating and quenching process that resulted in a lustrous purple-black patina resistant to tarnishing. Light silver-gray granite usually from one of four areas between Bodmin Moor and Land's End in Cornwall, England, the most important quarries being between aat:300011200 Cornish granite Falmouth, Camborne, and Helston. aat:300011574 Cream Blanc A type of Alabama cream marble that is hard, fine-grained, and creamy white in color; similar to Madre Cream. Term used in the glass trade for an opal glass which has been acid finished and had various ornate designs embedded in the glass in shades of brown and beige. A type aat:300206397 Crown Milano of art glass, developed by the Mt. Washington Glass Company. aat:300252429 Damascus steel Steel ornamented with wavy paaterns and noted for its hardness; formerly used especially for making sword blades. An easily worked, fine-grained siliceous sandstone from Wisconsin that is buff or cream in color. Like many varieties of sandstone, it is soft when first quarried but aat:300011413 Dunville sandstone gradually hardens as its moisture evaporates. aat:300238015 Dutch metal An alloy of copper and zinc, often used as a substitute for gold leaf since the 19th century. aat:300010986 Dutch white metal A type of britannia metal that contains 81.5% tin, 7.5% antimony, and 9.5% copper. aat:300011459 Egyptian breccia marble A coarse breccia marble containing fragments of pophyry, basalt, quartz, and granite in a greenish or purplish ground. aat:300011487 Eleusinian marble A fine, black marble from aatica, prized in ancient Greece, especially for friezes and interior decoration. aat:300010984 English britannia metal A type of britannia metal that contains 94% tin, 5% antimony, and 1% copper. aat:300010987 English pewter Pewter of the 16th century containing 91% tin and 9% antimony. aat:300013576 English vermilion Type of wet-process vermilion, originally made in England. Trademark name for a type of glass developed by Tiffany and Company with an iridescent surface simulating that of excavated ancient Roman glass; this effect was aat:300206359 Favrile glass (TM) produced by spraying the surface of the glass while hot with metallic salts. aat:300010561 Flemish brick Hard, yellowish paving brick. Plastic laminate made by bonding layers of materials such as canvas, glass, paper, or linen with thermosetting resins. May be used to refer to the trademarked product aat:300014581 Formica (TM) and to similar materials. aat:300011510 Formosa marble A gray and white mottled marble, sometimes also with red blotches, from Nassau, Germany. It often contains a large quantity of fossils. A high grade of massive talc occurring in the Appalachian region in the United States that can be cut to shape and used for marking purposes; it is usually white in color aat:300011161 French chalk but may be colored gray or yellow by impurities. Type of interlocking roof tile, heavily corrugated and formed with interlocking side joints and a rounded bull nose butt edge to engage the corrugations of the course aat:300010703 French tile immediately below. Any of several coarse-grained, pale-colored marbles quarried in northern Georgia. White Georgia is used for statuary. The others, such as Georgia Cherokee and Silver aat:300380382 Georgia marble Georgia gray, are used as interior and exterior building stones. Copper-nickel-zinc alloy, typically 20% zinc, 18% nickel, and the balance copper, used as a base metal for plated silverware, for springs and contacts in electrical aat:300136730 German silver equipment, and for corrosion-resistant objects. Limestone formed from pelagic sediment, specifically the ancient ocean bottom layer of soft mud, or “ooze," made from the shells of dead sea creatures belonging to aat:300387023 Globigerina limestone the genus Globigerina. It is the chief building material of the Maltese islands. Formerly copyrighted name for a series of alkyd resins used for surface coatings such as varnishes, shellacs and paints. Glyptal is made by heating phthalic anhydride aat:300387425 Glyptal and glycerin together. Trade name for a Teflon (TM)-based membrane filled with many minute pores which make it breathable yet waterproof and vapor proof. Its most common use is as a aat:300263388 Gore-Tex (TM) laminate between layers of cloth in all-weather clothing and footwear. aat:300011524 Griotte marble A purplish red marble, sometimes with white spots, found in the valley of Barouse and other areas in the French Pyrenees. aat:300010988 Hanover white metal A type of britannia metal that contains 87% tin, 7.5% antimony, and 5.5% copper. A bluish white marble with bands of parallel gray lines that originates from Mount Hymettus, near Athens, Greece. It can sometimes be slightly green in color, due to the aat:300011580 Hymettian marble presence of tiny veins of talc and it gives off a fetid odor when sawn or rubbed which is why it is sometimes called onion marble or marmor cipolla. Hymettian marble was often used for both pagan and Christian sarcophagi. Transparent, naturally-occurring calcite crystal used in demonstrating the polarization of light. An oblong stone made of Iceland spar found in the wreck of a 16th- aat:300380526 Iceland spar century English warship in 2013 has led archaeologists to speculate that the crystal is one and the same as the sunstone, a near-mythical navigational aid said to have been used by Viking mariners. In the glass trade, a type of art glass developed and produced by the Württembergische Metallwarenfabrik, Göppingen, ca. 1930, characterized by decorations aat:300255964 Ikora-Kristall created through inlaid patches or strips of color, often in combination with paaterned air bubbles. A nickel-chromium alloy, developed by the International Nickel Co., that is used for food and dairy equipment. It contains 79.5% nickel, 13% chromium, 6.5% iron, and aat:300179285 Inconel (TM) 0.08% carbon, as well as small amounts of copper, manganese, and silicon. A noncrystalline massive rock with aggregate filler and a matrix of 98% calcium carbonate in gray and buff colors; it is an oolitic limestone with small round grains aat:300011321 Indiana limestone resembling fish roe. Almost half of all the limestone used in the United States in block form is Indiana limestone. A rare, naturally occurring metallic element with symbol In and atomic number 49. Indium is a soft, silver-white metal collected as a residue of zinc-processing aat:300386618 Indium operations and chiefly used in the manufacture of semiconductors. Also appears as an impurity in ancient metal objects. aat:300197658 Invar (TM) A low-expansion iron alloy containing about 36% nickel; used for precision surveying instruments and timepieces. A predominantly pale green marble with white markings that is quarried on the island of Iona. A metamorphosed dolomitic limestone, it is considered to be one of two aat:300011514 Iona marble true marbles native to the British Isles, the other being Connemara marble. aat:300011488 Irish black marble A compact marble found in counties Galway and Kilkenny in Ireland that is considered one of the best black marbles. aat:300011584 Istrian marble A large-grained, buff marble quarried in Istria on the Adriatic Sea and on some of the Dalmatian islands. Pale yellow, soft, waxy substance obtained from the berries of Toxicodendron vernicifluum, the sumac tree native to Japan, and Toxicodendron succedaneum. It is not a true wax, but a fat. Japan wax is a byproduct of lacquer manufacture; it contains palmitic acid, stearic acid, and oleic acid with japanic acid. Japan wax is sold in flat aat:300014610 Japan wax squares or disks and has a rancid odor. It is used in the manufacture of candles, pharmaceuticals, cosmetics, floor waxes, furniture polishes, pastels, crayons, buffing compounds, metal lubricants, adhesives, and as a substitute for beeswax. aat:300014309 Japanese tung oil Oil derived from the nuts of the tree Aleurites cordata. It does not gelatinize when heated and is used for varnishes, waterproofing, paper and soaps. An aromatic oleoresin obtained from the red pine, Pinus resinosa, from trees in the Vosges mountains in France. An aromatic oleoresin obtained from the red pine, Pinus aat:300012903 Jura turpentine resinosa, from trees in the Vosges mountains in France. A hard, white, high-strength, quick-setting finishing plaster that takes a high polish; it is made by heating gypsum at a high temperature, grinding it to a powder, and aat:300010403 Keene's cement then adding alum to accelerate the set. It is often used as an interior plaster in areas that are treated roughly and in areas with a high level of moisture. aat:300011323 Ketton stone Oolitic limestone quarried in the vicinity of Ketton, Leicestershire, England; used primarily as a building stone. aat:300014467 Kevlar (TM) Trademark for a type of commercially produced aramid, a synthetic textile material which is lightweight, nonflammable, and has a high impact resistance. aat:300010989 Koeller's alloy Pewter containing bismuth, used in making utensils. aat:300011526 Languedoc marble A compact marble of brilliant red color blotched with white and found in Montagne Noir and other regions in the Pyrenees. Resembles griotte marble. aat:300380310 Lasa marble White marble with grey/black veins or speckling quarried in Val Venosta, Alto Adige, Italy. A type of white marble with a medium fine texture from Lee, Massachusetts. It can sometimes be light gray in appearance. A small band of Lee marble was used in the aat:300011585 Lee marble Washington Monument in Washington, D.C. but it proved too costly; it was, however, used to build parts of the Capitol in the 1850s. A serpentinite from the Italian Riviera, between Spezia and Genoa. It is found in two varieties: one is purplish or mottled black and dark red with some green pebbles or aat:300264225 Levanto granite veins, the other is green with many white veins. It is difficult to work with but acquires a high polish. It may resemble some varieties of variegated marble from Tennessee in the United States. A naturally occurring yellow or greenish glass made of silica found in parts of the Libyan Desert, the Western Desert of west Egypt, and along the Libyan-Egyptian aat:300400674 Libyan desert glass border. Its origins remain a debated issue within the scientific community, but may be the result of a meteor impact fusing desert sand. The glass was used as a gemstone by the ancient Egyptians, and also as a material for paleolithic tools. aat:300011619 Lisbon yellow marble A compact yellow marble from Estremoz, Portugal; it somewhat resembles Siena marble but is inferior. aat:300014434 Lucite (TM) Methyl methacrylate made by E. I. du Pont de Nemours and Company, Inc., marketed in rolling powder and in rolls, tubes, and cast and molded sheets. aat:300011468 Lyonaise marble Tradename of a coarsely mottled marble from Malletts Bay on Lake Champlain. Hard, quick-setting cement made of dehydrated gypsum to which is added a small percentage of calcined sodium sulfate and potassium sulfate; used for walls, and for aat:300010406 Mack's cement floors, when mixed with sand. aat:300011575 Madre Cream A type of Alabama cream marble that is hard, fine-grained, and creamy white in color; similar to Cream Blanc. A soft variety of copal resin obtained from species Agathis dammara native to the Philippines and Indonesia. It is used for varnishes and resin/oil media, and in many aat:300012918 Manila copal fixative recipes. Malleable resin with a pungent odor obtained from the Pili tree, Canarium indicum of Indo-Malaysia. Malleable resin with a pungent odor obtained from the Pili tree, aat:300012931 Manila elemi Canarium indicum of Indo-Malaysia. A compact, semi-crystalline magnesian limestone from Minnesota, ranging in color from buff, cream, yellow, gray, pink, or reddish buff. It is commonly used for building aat:300179301 Mankato stone as well as for decoration. Refers to a brass alloy of copper, zinc, and tin, with the appearance of silver or gold. Invented and largely produced in Mannheim, Germany, it was especially in use in aat:300265140 Mannheim gold the early 18th century. Mannheimer gold was often used to make inexpensive jewelry. A viscous, oleoresin obtained from South American deciduous trees of the genus Copaifera native to Venezuela, containing 40% copaiba oil. A viscous, oleoresin obtained aat:300012901 Maracaibo balsam from South American deciduous trees of the genus Copaifera native to Venezuela, containing 40% copaiba oil. Traditional type of soap made from olive oil or other vegetable oils, in the area of Marseilles, France since ca. 1370. In 1688 Louis XIV introduced regulations limiting the aat:300266167 Marseilles soap use of the name "savon de Marseille" to soaps made in and around the Marseilles area and only made from olive oil. Today this law still applies, although other vegetable oils may now be used. Often used for cleaning and degumming textiles. aat:300010407 Martin's cement Cement made with potassium carbonate instead of alum. Plastic laminate made by bonding layers of cloth or paper with a resin under heat and pressure; made in sheet, rod, and tube form, and in other molded shapes. May be aat:300014582 Micarta (TM) used to refer to the trademarked product and to similar materials. A coarse biotite granite, quarried in Milford, Massachusetts, composed mostly of light pink feldspar with additions of gray quartz and dark, greenish-black flecks of a aat:300011203 Milford granite chloritic black mica. It is very strong, takes a high polish, and has a fine and close texture, making it one of the most desirable granites quarried in the U.S. for general building as well as decorative purposes. aat:300011207 Minnesota red granite A flesh red granite that is found in abundance in Minnesota. aat:300011591 Missouri marble A white to light gray marble with a blue or gray tint; it is coarse-grained and contains some stylolites. Mondragone marble is a slightly metamorphosed yellow or gray carbonate rock, which was widely employed as monumental stone in the 18th-century royal palaces of aat:300387366 Mondragone marble Naples and Caserta. Named for Mondragone, Campania where the marble is quarried. aat:300133244 Monel (TM) Alloy composed of about 67% nickel, 28% copper, and 5% other elements such as iron. aat:300010950 Muntz metal Brass containing 60% copper and 40% zinc, commonly produced in sheets. Distinctive glass produced on the island of Murano, located off Venice, Italy. Murano was well-known for glassmaking by the 10th century. Even though Murano aat:300380561 Murano glass glassmakers have emigrated elsewhere, experts and commercial markets usually hold that authentic Murano glass is fabricated only in Murano. Most Murano glass is made using the lampworking technique. aat:300014480 Mylar (TM) Clear coated polyester film. A type of art glass developed and produced by the Württembergische Metallwarenfabrik (W.M.F.) by Karl Weidman ca. 1926. It is characterized by the use of colorless, aat:300266116 Myra-Kristall raw glass made iridescent by a silver stain and then maate fired, resulting in a shimmering metallic surface. aat:300411856 Nordic gold A copper alloy containing copper (89%), aluminum (5%), zinc (5%), and tin (1%). aat:300163743 Norman brick Brick whose nominal dimensions are 2 2/3 by 4 by 12 inches. Refers to a type of glass that was invented during the Gothic Revival in the 19th century and is characterized by an uneven thickness that is thicker in the center, and aat:300263716 Norman slab glass thinner on the edges. It is made by blowing the molten mixture into a rectangular mold, or by blowing and molding a bubble of glass into a box shape, then cutting the sides of the box to form rectangles of glass. The glass may be clear or colored. A dark bluish gray sandstone quarried on the west side of the Catskill Mountains near the Delaware River (formerly North River) in New York. In the 19th century, North aat:300011389 North River bluestone River bluestone was used for sidewalks and curbs. aat:300011557 Numidian marble The color of this marble ranges from yellow, light brown, and pink to deep red. It originates not from Numidia proper, but from the mountains of Algeria and Mauritania. aat:300411306 Opalon (TM) Trade name of a type of thermosetting resin, manufactured by Monsanto. aat:300010408 Parian cement Similar to Keene's cement with borax instead of alum as a setting accelerator. A pure white marble with transparent and flaky crystals; quarried on the island of Paros in the Cyclades, it was used by the ancient Greeks for sculpture as well as aat:300011594 Parian marble architecture. A famous Greek marble quarried at Mount Pentelikon near Athens. It is pure white but may turn yellow after long exposure to air; a few miniscule veins of talc aat:300011599 Pentelic marble sometimes cause a faint greenish tint. It was used in antiquity as early as the 6th century BCE and continued to be popular for both sculpture and architecture; both the sculptural decoration and the architectural members of the Parthenon are made of Pentelic marble. Commercially produced, British acrylic plastic consisting essentially of polymerized methyl methacrylate. Polymethyl methacrylate was discovered in the early 1930s by aat:300014435 Perspex (TM) British chemists at Imperial Chemical Industries in England and trademarked the name Perspex. A dark brown oleoresin obtained from Myroxylon balsamum var. pereirae trees that are native to the coastlines of Central America. Peru balsam contains high amounts of cinnamic acid, benzoic acid, and vanillin. It is used for perfumes and flavorings. Peru balsam has also been used as a dark brown glaze for paintings. Peru balsam is aat:300012904 Peru balsam (balsam) very similar to Tolu balsam, dervied from a variety of the same species. A dark brown oleoresin obtained from Myroxylon balsamum var. pereirae trees that are native to the coastlines of Central America. Peru balsam contains high amounts of cinnamic acid, benzoic acid, and vanillin. It is used for perfumes and flavorings. Peru balsam has also been used as a dark brown glaze for paintings. Peru balsam is very similar to Tolu balsam, dervied from a variety of the same species. Proprietary name for polymerized methyl methacrylate, used as a substitute for glass in products such as windows, skylights, illuminated signs, and aircraft. Plexiglas aat:300014436 Plexiglas (TM) was trademarked by Rohm and Haas AG in Germany ca. 1930s. Term used in the glass trade for a type of art glass made by the New England Glass Company in 1885, consisting of clear glass enlarged by repeated mold blowing and aat:300207397 Pomona glass decorated with a network of acid etched lines, or having a mottled surface created by rolling the vessel in an acid resistant substance and then acid bathing. A purplish red and white clouded stone which may come from either the island of Iasus or the island of Chios. It was supposedly favored by the emperor Claudius in aat:300011567 Porta Santa marble antiquity and was later used in the door jambs of the Porta Santa of St. Peter's in Rome, hence its name. aat:300011404 Portland sandstone Stone of English origin consisting of fossils cemented together with lime. aat:300011324 Portland stone (limestone) An oolitic limestone widely used for building in England, particularly in London; it is quarried on the Isle of Portland, off the coast of England. A striking breccia quarried in the Blue Ridge Mountains in Maryland and Virginia; it consists mostly of limestone, quartz pebbles, and multicolored fragments ranging aat:300011426 Potomac breccia from sand grains to cobbles, all cemented together in a calcareous matrix. It can be extremely difficult to work as the hard pebbles tend to break away from the softer matrix. A siliceous sandstone, from Saint Lawrence County in New York, containing a small amount of iron oxide, giving it its red or reddish-brown color. Although soft enough to aat:300011417 Potsdam sandstone work economically when first quarried, it becomes incredibly hard upon exposure, making it an incredibly durable building stone. A bright, natural red volcanic pigment originally mined at Pozzuoli near Naples, Italy. It was used by the Romans and others as a paint pigment, becoming popular for aat:300013549 Pozzuoli red (pigment) fresco paintings because it dried quickly to a hard impenetrable surface like cement. Refers to an alloy used in the jewelry and watch trade during the 17th and 18th centuries, mostly in England; it was golden in color and was probably an alloy of copper aat:300265142 Prince's metal and zinc that resembled brass. Some sources specifically describe it as a type of brass with a composition of three parts copper to one of zinc pickled in a diluted spirit of vitriol and then immersed in aquafortis before burnishing. Prince's metal was supposedly invented by Prince Rupert of the Rhine. A coarse variegated marble, quarried on the island of Proconnesus, present-day Marmara Adasi, Turkey, that is either gray, white, or white with gray stripes. Large aat:300193786 Proconnesian marble quantities of this marble were imported to Greece to be carved into sarcophagi. Also called Cyzican marble because it was used extensively in Cyzicus, present-day Belkis, as it was in Constantinople as well. Stone quarried in the vicinity of the Isle of Purbeck peninsula, Dorset, England; used primarily as a building stone. It is actually a hard semi-metamorphosed limestone aat:300011308 Purbeck marble formed from the shells of snails. Given that the stone is hard enough to take a fine polish it is called "Purbeck marble," even though it is not fully metamophosed marble. aat:300010801 Pyrex (TM) A low-expansion type of bora-silicate glass. A light brown or buff-colored dolostone that is well-cemented, free of jointing, and ideally suited for building purposes. It is often used as a building stone in Toronto, aat:300130964 Queenston limestone Canada as it is quarried in southern Ontario; Queenston limestone caps the Niagara Escarpment. Before a quarry operation was begun at Queenston in about 1840, Scottish settlers exploited the limestone beds for building materials; the present quarry is one of the oldest in Canada. aat:300011395 Reigate stone Calcareous sandstone quarried in the vicinity of Reigate, Surrey, England; used primarily as a building stone. aat:300151452 Rhoplex resin (TM) Acrylic resin emulsion of the Rhom & Haas Company, used in paint, textile finish, and adhesive. aat:300011494 Rockingham royal black marble A jet black marble with irregular white veins, occurring in Virginia, that is considered the best American black marble. aat:300010505 Roman brick Brick whose nominal dimensions are 2 2/3 x 4 x 12 inches. aat:300264905 Roman classic travertine Refers to a type of travertine that is beige, cream, honey, and/or gold in color; it is lighter in color than barco. aat:300010991 Roman pewter Ancient pewter containing 70% tin and 30% lead, with other elements such as iron present as impurities. aat:300010717 Roman tile A channel-shaped, tapered, single lap, roofing tile. aat:300386784 Rosa Porriiño granite A durable, dense, pink dolerite granite from quarries in and around Porriiño, Galicia, Spain. aat:300010499 SCR brick Brick wider and longer than most other brick; used chiefly for garden walls. aat:300011495 Saint Anne marble A deep blue-black marble with short white veins that is found in Saint Anne, Belgium. aat:300011464 Sarrancolin marble A variegated French breccia marble, usually with gray, red, or yellow predominating, quarried near Sarrancolin in the Pyrenees. A fine-grained red, reddish-brown, and gray sandstone from Seneca Creek, Maryland; it contains coarse- to fine-grained angular quartz as well as some feldspar and mica fragments. It is fairly easy to carve but darkens and hardens when exposed to air, making it one of the most durable building stones. Seneca sandstone was aat:300011405 Seneca sandstone extremely popular in Washington, D.C. during the 'brownstone era' of about 1840 to 1880; the original Smithsonian Institution building, for example, is made of Seneca sandstone. A pinkish-red and gray English granite that is distinguished by embedded crystals of red felspar, sometimes as long as 2 inches. There are 2 distinct shades, Light Shap aat:300011204 Shap granite and Dark Shap. aat:300081349 Sheffield plate Plate consisting of an overlay of silver on copper, brass, or other metal so as to simulate solid silver. Yellow and light brown marble quarried near Siena, Italy that is sought after for interior architectural use, both in the past and in the present; it is compact and often aat:300011620 Siena marble brecciated, with a waxy lustre. A medium-hard, pale yellow variety of copal resin obtained from trees of the genus Copaifera native to Sierra Leone, Guinea, and Ghana. It has been used in varnishes. aat:300012920 Sierra Leone copal A medium-hard, pale yellow variety of copal resin obtained from trees of the genus Copaifera native to Sierra Leone, Guinea, and Ghana. It has been used in varnishes. Dammars shipped under the tradename "Singapore" from the island of Singapore. Singapore dammar is paler than Batavian dammar and has less tendency to bloom. aat:300012926 Singapore dammar Dammars shipped under the tradename "Singapore" from the island of Singapore. Singapore dammar is paler than Batavian dammar and has less tendency to bloom. aat:300011349 Solnhofen stone An exceedingly fine and even-bedded magnesian limestone, thinly stratified, quarried in the vicinity of Solnhofen, Bavaria, Germany; widely used in lithography. An earth pigment containing red iron oxide, originally obtained from Spain. It is a coarse grain, an inexpensive colorant, having a dull red color, and used in industrial aat:300013558 Spanish red oxide (pigment) paints. aat:300010719 Spanish tile Clay roofing tile, approximately semicylindrical in shape; laid in cornices with the units having their convex sides alternately up and down. A siliceous sandstone from Derbyshire, England; it is also considered a gritstone, specifically a Darley Dale gritstone. It is even-grained and exceedingly hard, making it aat:300011418 Stancliffe sandstone an excellent choice for ashlar and paving work. Its silica content is so high, however, that trade unions have been known to ban its use owing to the danger of silicosis; whenever possible, Stancliffe sandstone is now only worked by wet methods. An aromatic, thick, viscous exudation obtained from several Central European fir trees, including Abies alba. Strasbourg turpentine contains about 57% resinous acids, aat:300012906 Strasbourg turpentine 28% terpenes, and 13% resins. It is similar to Venice turpentine and has been used since the 16th century as an additive to oil paints, mastic, and other varnishes. aat:300014568 Styrofoam (TM) Polystyrene expanded into a multicellular mass that has one-sixth the weight of cork and will withstand temperatures above 170 degrees Fahrenheit. A shell marble from Sussex, England that is predominantly gray with occasional green or blue tinges. Its old local name, 'winklestone,' refers to the abundance of small aat:300011481 Sussex marble snail shells (winkles) embedded in the marble. Used to ornament churches in the Middle Ages, it remained popular for centuries. aat:300011339 Tabriz marble Onyx marble quarried in the vicinity of Tabriz, North Western Iran. It is used primarily as a building stone. Among the most important types of rock used for garden building in China. A type of limestone categorized according to its northern and southern varieties, it is found aat:300391363 Taihu rock both underwater and in the mountains. The type found in Lake Taihu in Jiangsu province is the most well-known variety, and thus “Taihu rock” has become a general designation for such stones. A fine pink marble, suitable for sculpture, of which a number of varieties exist. Tennessee marbles are generally harder and more compact than other American marbles, aat:300011522 Tennessee Pink marble making them more suitable for outdoor use but also making them more difficult to carve and polish. A coarse, variegated marble from Hawkins County, Tennessee. It is dark chocolate brown or red in color with white streaks and masses throughout and it usually aat:300011611 Tennessee marble contains some fossils. A coarse-textured white marble that is nearly pure calcium carbonate; it was used to build the first 152 feet of the Washington Monument in Washington, DC. It is aat:300011610 Texas marble quarried in Texas, Maryland, not in the state of Texas. aat:300013559 Tuscan red A bright red pigment prepared by depositing an organic red dye, such as alizarin, on a red iron oxide base. aat:300010992 Tutanic metal German utensil alloy, contains 88% to 92% tin, up to 3% copper, and 6% to 7.5% lead. Refers to distinctive glass made in Venice, Italy. It can refer to early glass made from about 450 CE when glass-makers from Aquileia fled there and were soon joined by others from Byzantium. In addition, the term is particularly used to refer to glass made on the Venetian island of Murano from before 1292 to the present day. It is generally a sodiac type of glass; soda glass is light in weight and highly ductile. Venetian glass incorporates a number of styles and techniques although Venetian glass- aat:300136735 Venetian glass makers particularly excelled in the making of colored glass, agate glass, opaque white glass (laatimo), cristallo, filigrana, and millefiori. Engraving is rarely found while enameling and gilding are common, particularly in fifteenth- and sixteenth-century specimens. In order to protect their profits and the secrets of Venetian glass, the Venetians confined glassmakers under pain of death to the island of Murano; however, the techniques were eventually imitated in "Altare glass" and "façon de Venise." For glass made exclusively on Murano, see "Murano glass." A permanent, reddish brown pigment that was originally prepared from a natural red ocher, but since the 18th century has been manufactured by calcining ferrous aat:300013560 Venetian red (pigment) sulfate (copperas) with lime or calcium carbonate in a ratio of around 15-40% ferric oxide and 60-80% calcium sulfate. It is used in oil paints, house paints, and as a paper colorant. A thick, viscous exudation from the Austrian larch tree, Larix decidua, containing 63% resinous acids, 20% terpenes, and 14% resins. It has been used since the 16th century in small amounts to produce an enamel-like surface that is non-yellowing. However, it is not used as a varnish because it quickly becomes dark and brittle when exposed to oxygen and light. It is also used as a mounting medium for light microscopy and as a plasticizer in glue paste linings. A thick, viscous exudation from the aat:300012908 Venice turpentine Austrian larch tree, Larix decidua, containing 63% resinous acids, 20% terpenes, and 14% resins. It has been used since the 16th century in small amounts to produce an enamel-like surface that is non-yellowing. However, it is not used as a varnish because it quickly becomes dark and brittle when exposed to oxygen and light. It is also used as a mounting medium for light microscopy and as a plasticizer in glue paste linings. aat:300011615 Vermont white statuary marble A fine-grained white marble from Vermont that is highly valued by sculptors; it may contain bluish-gray veins or clouds. aat:300183986 Vinylite (TM) Trademarked name for a vinyl resin used in the production of phonograph records. aat:300010863 Vitrolite (TM) Refers to thick homogeneous opaque structural glass used especially for ornamental finish on surfaces exposed to the weather. aat:300011326 Weldon stone Oolitic limestone quarried in the vicinity of Weldon, Northhamptonshire, England; used primarily as a building stone. aat:300011616 White Cherokee marble A white marble with black and gray blotches from Pickens County, Georgia; it is coarser than white marble from Vermont. aat:300011201 Wicklow granite A gray granite native to Wicklow, Ireland. aat:300011617 Winooski marble A red and brown marble variegated with white dolomitic, quarried near Winooski, Vermont. A bluestone that is similar to Hudson bluestone and other bluestones from New York; it is characterized by a fine, compact texture and a dark blue-gray color. It is aat:300011390 Wyoming Valley stone considered one of the most valuable stones found in Wyoming for building and flagging purposes. A variety of copal resin that is hard and found on the island of Zanzibar and areas of nearby African mainland. It is derived from either semi-fossilized specimens or as exudations on species Hymenaea verrucosa. The most valued pieces are fossilized specimens found embedded in the earth over a wide belt of East Africa on the western coast of Zanzibar, on tracts where not a tree is now visible. Zanzibar copal is a very hard, smooth, and shiny resin that is used to make a dark oil varnish, for fumigation, and in perfumery. Some specimens of Zanzibar copal are misrepresented as amber. A variety of copal resin that is hard and found on the island of Zanzibar and areas of aat:300012921 Zanzibar copal (resin) nearby African mainland. It is derived from either semi-fossilized specimens or as exudations on species Hymenaea verrucosa. The most valued pieces are fossilized specimens found embedded in the earth over a wide belt of East Africa on the western coast of Zanzibar, on tracts where not a tree is now visible. Zanzibar copal is a very hard, smooth, and shiny resin that is used to make a dark oil varnish, for fumigation, and in perfumery. Some specimens of Zanzibar copal are misrepresented as amber. aat:300010757 Zonolite concrete (TM) A form of concrete which acts as an insulator. A laminated leaf, resembling gold leaf, was made by placing a thin sheet of gold over a similar sheet of silver (or tin) and hammering the two together. The gold-silver aat:300264834 Zwischgold laminate was used instead of gold leaf, but it had the undesirable characteristic of tarnishing, since the thin gold layer cannot protect the silver below. aat:300011833 abalone shell Bowl-like shells of the abalone mollusk, a source of mother of pearl. aat:300343502 acacia gum A type of high quality gum arabic. A red or yellow resin obtained from the base of Tasmanian and Australian grass trees of the Xanthorrhoea family; different species produce different colors of resin. The aat:300012883 acaroid resin resins are chemically similar to balsams and contain some cinnamic acid; they produce hard, insoluble films. They are used for varnishes, metal lacquers, surface finishes for leather and paper, substitutes for rosin, sealing waxes, and inks. Treatment with sulfuric acid produces a lightfast brown-black dye. aat:300010425 accelerated cement Cement that will set hard in three days. aat:300014421 acetal (thermoplastic) Highly crystalline resin that is among the strongest and stiffest types of thermoplastic. A colorless hydrocarbon gas, the simplest of the alkynes, also called ethyne. Acetylene burns much more brightly than other gases and was used for stage lighting aat:300380475 acetylene before electric lights were introduced. It burns with an intensely hot flame and is widely used as a fuel in oxyacetelene welding, soldering, and cutting of metals. aat:300011180 acid igneous rock Igneous rock containing a high percentage of silica; examples are granite and rhyolite. Colorless, transparent, thermoplastic synthetic resin made by the polymerization of acrylic acid derivatives; used for adhesives, fibers, consolidants, protective coatings, aat:300014426 acrylic (plastic) finishes, and as a paint medium. A clear, colorless, poisonous liquid which can be polymerized to form acrylic and modacrylic fibers. It is coplymerized with butadiene to create nitrile rubber. Acrylonitrile aat:300380476 acrylonitrile is also used as an insecticide. Thermoplastic with applications in appliance, automotive, and business machine manufacture, among others. Available in varied grades, ABS consists of discrete , aat:300014418 acrylonitrile-butadiene-styrene copolymer crosslinked rubber particles that are grafted with polystyrene-co-acrylonitrile and embedded in a SAN matrix. Carbonaceous material, especially charcoal, activated by heat at high temperature, or otherwise treated to increase its porosity and adsorptive power. Activated carbon aat:300380477 activated carbon is used in removal of pollutants from gas and liquids and in other purification processes. aat:300010955 admiralty metal Alloy consisting of about 70% copper, 1% tin, and the remainder zinc. Handmade, sun-dried brick typically made from wet mud and straw, sometimes also containing sand, clay, dung, grass, chaff, or blood. It is porous, wettable, susceptible to wet-dry cycle degradation, but good heat insulation. Adobe walls are typically built using mud mortar between the brick layers followed with a mud stucco aat:300081138 adobe (material) finish layer. It was used as early as 7000 BCE for houses, buildings, and pyramids, particularly in arid climates such as Mesopotamia, Persia, Palestine, India, China, and the pre-Columbian Americas. For sun-dried brick that may or may contain the binders of adobe, use the more general "sun-dried brick." aat:300400863 aerinite (mineral) A rare, chemically complex carbonate-bearing silicate. Occasionally used in pigments. Gelatinous polysaccharide substance extracted from various species of Rhodophyceae red seaweed, that grow in the Pacific and Indian Oceans and the Japan Sea. Agar contains agarose and agaropectin. It is strongly hydrophilic and can absorb over 20 times its own weight in cold water. Agar dissolves in hot water and forms a stiff, clear jelly upon cooling. However, when agar films are desiccated, they shrink significantly. Most commonly used as a media for culturing bacteria and fungi, agar has also aat:300130954 agar been used for sizing textiles and paper, as an emulsifying agent in foodstuffs, photographs, dental mold materials, cosmetics, and adhesives, to make an experimental synthetic gauzelike fabric in England. Agar is available in dried cakes, coarse granules, long strips, and thin sheets. The primary commercial sources for agar are Japan, New Zealand, Australia, Russia, and the United States. According to legend, agar was first discovered in the mid-17th century in Japan. Cryptocrystalline chalcedony, showing a variegated banded structure and waxy luster. Agate bands are caused by the deposition of successive mineral layers from aat:300011135 agate (chalcedony) solution and may be either straight, wavy, or concentric. Agate is slightly harder than quartz. It has been gathered or mined since Neolithic times. It may distinguished from onyx by the parallel structure of the bars in onyx. Decorative opaque glass made by mixing different colors in order to imitate natural semi-precious stones such as chalcedony, jasper, and onyx as well as agate. Agate aat:300206149 agate glass glass was produced in ancient Rome and from the late 15th century onward was produced in Venice and Germany. It is similar in appearance to pâte de verre which is produced by a different process. The term also refers to a type of art glass developed by Tiffany that resembles agate stone. aat:300213004 air (material) A mixture of gases comprising the earth's atmosphere generally understood as that which is essential to the survival of land animals and plants. aat:300010527 air brick A perforated brick or perforated metal unit of brick size which is built into a wall for ventilation. aat:300010760 air-entrained concrete Concrete containing minute air bubbles that improve its workability and frost resistance. Fine-grained marblelike variety of gypsum that is easy to carve but is rather fragile; it has been used as a sculpture material, ornamental building work, vases, small aat:300011101 alabaster (mineral) decorative carvings, and powdered for use as a paper filler and paint pigment called mineral white or terra alba. Alabaster is usually a translucent white or pink but may also be a muted red, yellow or gray. It is soft and can be scratched slightly with a fingernail. It also dissolves slowly in wet environments. aat:300209712 albite A white or colorless triclinic mineral of the feldspar group. Water-soluble and alcohol-soluble protein obtained from egg, blood, or milk; used in adhesives, finishes, coatings, varnish, as a clarifying agent for tannin, and in oil aat:300011794 albumin (general protein) emulsion. The spelling with "i" is typically reserved fro this broader meaning. Use "albumen (egg white)" (spelled with an "e") for egg-white protein in the context of food preparation or photography. Limestone composed largely of the remains of calcium-carbonate-producing algae, or one in which such algae serve to bind together the fragments of other calcium- aat:300011289 algal limestone carbonate producers. Cellulose, usually derived from wood pulp or cotton linter, that is treated with an alkali, such as sodium hydroxide; used to produce viscose rayon and other cellulose aat:300249863 alkali cellulose derivatives. aat:300210989 alkali feldspar Feldspar used in the manufacture of ceramics and glass, as well as gemstones. aat:300391242 alkaline sulfite A sulfite having a base that is alkaline. Examples of uses include in a chloride extraction treatment to stabilize corroded marine cast iron, and in wood pulping. A member of the series of saturated hydrocarbons with the general chemical formula CnH2n+2, where "n" is a whole number. Though generally nonreactive, they aat:300264226 alkane combust readily and many important fuels are alkanes, such as methane and butane, or mixtures of alkanes such as gasoline. Any of a variety of synthetic resins, produced by the esterification of a polybasic acid with a polyhydric alcohol. Often used for coatings, finishes, adhesives, and molding aat:300014518 alkyd resin compounds. aat:300380053 alkylalkoxysilane Refers to hydrophobic silane used as coating on stone or concrete to repel water. Substance having metallic properties, consisting of two or more metallic elements or of metallic and nonmetallic elements, which are miscible with each other when aat:300010902 alloy molten, and do not separate into distinct layers when solid. A general name for steel that owes its distinctive properties to elements other than carbon; types of alloy steel typically take the name of the element or elements that aat:300010917 alloy steel are most influential on their character. Usually used for toolmaking and building. A deposit of earth, sand, and other transported maater left by water flowing over land not permanently submerged; chiefly applied to the deposits formed in river valleys aat:300264223 alluvium and deltas. aat:300014520 allyl resin Resin made by polymerization of chemical compunds containg the allyl group. A type of red garnet composed of iron aluminum silicate. Almandine can range in color from pale violet to bright red, or from purplish to brownish black. Almandine was aat:300380120 almandine a popular gemstone in antiquity, particularly in ancient Rome and Egypt. Today, gemstone quality almandine is mined in Asia Minor, Sri Lanka, Australia, Alaska, Africa, Norway, Sweden, and Japan. aat:300014318 almond oil A colorless or pale yellow bland and nearly odorless nondrying faaty oil used as an emollient. Colorless-to-white crystalline potassium aluminum sulfate; has a wide range of uses, including in treatment of leather and textile, in sizing paper, as a mordant in aat:300183621 alum dyeing, and as a water-purifying agent. aat:300010364 aluminous cement Cement made with bauxite and containing a high percentage of alumina; valued for its fast setting and high strength properties. aat:300010943 aluminum bronze A copper-aluminum alloy with aluminum as the chief alloying element. A thin leaf used in gilding for a silvery effect. Because of its relatively dull, leaden appearance, aluminum leaf is an inferior substitute for silver leaf and palladium leaf. It aat:300265201 aluminum leaf is mainly used in the commercial arts. Type of bronze powder made from pure aluminum or an aluminum alloy, commonly used as a pigment in industrial paint, ink, plastic, and caulking compound, and as a aat:300248317 aluminum powder textile coating. A hard, thermoplastic white powder that used as a drier, thickener, emulsifier, and maating agent in paints and varnishes; excess amounts produce soft, noncohesive aat:300266845 aluminum stearate films. Aluminum stearate is also used to waterproof fabrics, ropes, paper, leather, concrete, and stucco. It is used as an ingredient in photographic emulsions. It forms gels with turpentine, mineral spirits, and oils. White crystalline salt found naturally as mineral alunogenite; made synthetically by treating bauxite with sulfuric acid. It is used as a dye mordant, in tanning, as a aat:300387539 aluminum sulfate flocculant in water purification, and for sizing paper. aat:300010937 aluminum-silicon alloy Refers to alloys with from 5 to 22% silicon characterized by ease of casting, corrosion resistance, lightness, and ease of welding. aat:300189775 amalgam Alloy of mercury with another metal. A yellowish, hard, glassy, translucent fossil tree resin found in largest deposits on the Baltic coast and dating 40-60 million years old. Types of amber are classified by location. Amber is composed of complex mixtures of oxidized and polymerized resin acids and resin alcohols. It has been gathered or mined since Paleolithic times. It is aat:300012934 amber (fossil resin) easy to carve and was often used in its natural state for jewelry, beads, amulets, and small vessels. It was also used as an ingredient in paint; dark color oil and amber varnishes are made by dissolving melted amber in amber oil, turpentine oil, or a drying oil. It develops an electrical charge when rubbed with a cloth. It is also valued because very ancient insects and plants may be preserved in the amber. aat:300011133 amethyst (mineral) Purple or bluish-violet varieties of quartz, that have gathered or mined since Neolithic times. A serpentinite that may be white, yellow or gray but is rarely green or red. It is so flexible that the ancient Romans were said to have used it to make shrouds so that aat:300011629 amianto the ashes of the dead did not mix with those of the fuel. Any thermosetting plastic made by polycondensation of a compound containing amino groups such as urea or melamine, with an aldehyde, such as formaldehyde or aat:300014523 amino resin another aldehyde-yeilding substance. Amino resins were first made in 1929. Examples of amino resins are melamine formaldehyde and urea formaldehyde. Amino resins are used for molded plastics, coatings, adhesives, laminating, textile finishes, and paper manufacture. aat:300014531 aminoaldehyde resin Resin made by the interaction of an amine and an aldehyde. aat:300390552 aminosilane A group of chemically reactive silane compounds (organofunctional alkoxysilanes) Used in the context of paper conservation to deacidify and strengthen degraded paper. Colorless, pungent gas composed of nitrogen and hydrogen (NH3) in the simplest stable compound of these elements. It was the first complex molecule to be identified in interstellar space. Gaseous ammonia was first isolated by Joseph Priestly in 1774. It is used in the following ways: as a starting material for the production of many aat:300011767 ammonia (anhydrous ammonia) commercially important nitrogen compounds, such as in the manufacture of explosives and fertilizers; and as a vapor phase neutralizing/alkalizing agent where it neutralizes effectively but provides no residual alkaline reserve. Ammonia is most often sold as an aqueous solution of ammonium hydroxide. Refers to a carbonate of ammonium commonly known as hartshorn. It is a white powder used in smelling salts, baking powder, textile dyeing, and other applications. In aat:300379617 ammonium carbonate conservation, a solution of ammonium carbonate is used as a solubilizing agent for extraction of soluble salts present on deteriorated stone surfaces. aat:300183629 ammonium chloride White crystalline powder used in electric baateries, in printing, as a soldering flux, and in making other compounds. The hydroxy salt of ammonium ion, formed when ammonia reacts with water molecules in solution. It is an alkaline solution containing around 28.5% ammonia by aat:300266781 ammonium hydroxide (inorganic material) weight, highly soluble in water. For solutions containing this substance, use "ammonia water," though usage overlaps because ammonium hydroxide always or almost always exists only in solution. Refers to oxalate with ammonia commercially produced as colorless crystals used for dyeing textiles and in other applications. In conservation, ammonium oxalate in aat:300380079 ammonium oxalate solution is used as a treatment for calcium carbonate based surfaces (such as limestones, marbles, historical wall paintings). It forms a protective layer of calcium oxalate on surfaces through chemical reaction. Ammonium salt made from a reaction of sulfuric acid and ammonia. It is primarily produced by the destructive distillation of coal. Ammonium sulfate is a commercially aat:300389870 ammonium sulfate important chemical used as a fertilizer, food additive, and tanning agent. aat:300380044 amylase Digestive enzyme that breaks down starch by hydrolysis into its basic sugars. In conservation, used for removal of starch adhesives. aat:300011213 andesite An extrusive, usually dark grayish igneous rock consisting essentially of oligoclase or andesine feldspar with augite, hornblende, hypersthene, or biotite. A type of garnet composed of a calcium iron silicate. Colors include yellow, red, green, brown, and black. Gemstone quality andradite is mined in the Ural Mountains, aat:300379286 andradite Italy, Switzerland, Norway, France, and in the United States (Arkansas and New Jersey). It is valued because of its high dispersion (separation of light into colors), which is even greater than that of diamond, and refractive index. aat:300010465 angle brick Any brick having an oblique shape to fit an oblique salient corner. A colorless to white rock-forming mineral, named from the Greek “anhydrous” meaning without water. It is anhydrous calcium hydrate. An evaporate mineral, aat:300380482 anhydrite anhydrite hydrates readily to gypsum. A low-molecular-weight adhesive made from a solution of degraded or denatured collagen in water. The protein content in animal glue is less pure and darker in color aat:300192836 animal glue than gelatin. aat:300014256 animal oil Oil obtained from animal substances. Any of several waxes obtained from animal sources, found in small deposits in many parts of the animal. Animal waxes, such as from a mammal, typically contain no glycerides; they contain sterols (cholesterol) and other long-chain alcohols. Also included are the waxes from insects such as the lac insect which produces shellac. Any aat:300014586 animal wax of several waxes obtained from animal sources, found in small deposits in many parts of the animal. Animal waxes, such as from a mammal, typically contain no glycerides; they contain sterols (cholesterol) and other long-chain alcohols. Also included are the waxes from insects such as the lac insect which produces shellac. Term used indiscriminately to refer to soft, low quality copal resins, but particularly the resin obtained from the Hymenaea courbaril trees of South America. The name aat:300400815 anime (gum resin) has also been used for the hard, semi-fossilized, high-quality Zanzibar copal, but anime may be distinguished from other copals by being soft, clear, and alcohol-soluble. There are a number of other oleoresinous products also known as 'anime," or "gum anime." Ankerite is a carbonate mineral, a member of the dolomite group in which the magnesium is replaced in substantial part by iron, with or without manganese. Ankerite aat:300380335 ankerite occurs in deposits of iron ore and is also found in thin veins in coal seams. aat:300386564 anorthite A feldspar mineral used in the production of glass and ceramics. aat:300210995 anorthoclase A sodium potassium feldspar mixture containing albite and orthoclase. A colorless, crystalline compound derived from the fractional distillation of coal tar and composed of three aatached aromatic rings. It is used to make synthetic alizarin aat:300311163 anthracene (material) pigment, and to manufacture other organic dyes, resins, plasticizers, and tanning agents. Non-bituminous and most highly metamorphosed form of coal containing more fixed carbon and least amount of volatile maater than any other form. Anthracite is the aat:300015140 anthracite least plentiful form of coal. Class of protective proteins, naturally present in the body or produced by the immune system, which target harmful foreign substances, called antigens, in order to aat:300387554 antibodies remove them from the body. A type of serpentine that is soft, coarse-grained, with a dull, waxy color. Antigorite was used in Egypt in the Pharaonic period for small vessels, amulets, and scarabs. It aat:300379309 antigorite is named after the community of Antigorio, Italy, site of the specimen that was first described. Pure metallic element having symbol Sb and atomic number 51; a bright, hard, silvery to bluish white metal. Use also for this metal as processed and formed, usually in aat:300011017 antimony combination with other substances, to make various objects and materials, particularly alloys and pigments. aat:300013573 antimony vermilion Obsolete permanent pigment made of antimony trisulfide. Invented and patented by Murdock in Scotland in 1847, it was replaced by cadmium red in the 1920s. Material made from antlers, which are paired deciduous outgrowths of bone projecting from the frontal bones of ungulates of the deer family. Distinguished from "horn," aat:300011796 antler (material) which is modified skin tissue or compacted hair. Naturally occurring mineral of calcium fluor-phosphate; numerous deposits are found in Germany, Spain and North America. It is colorless when pure, but impurities can aat:300011070 apatite give it a white, green (asparagus stone), blue (moroxite), yellow, or violet color. Bones are composed of hydroxyapatite, mixed with protein (ossein) and small amounts of other minerals, such as calcium carbonate. Apatite is commercially used as a fertilizer. aat:300012867 apricot gum A clear, pale gum that exudes from apricot trees. aat:300011073 aquamarine (mineral) A transparent, light bluish green gem variety of beryl. Aragonite is a widespread mineral, a crystalline form of calcium carbonate that is found in deposits formed at low temperatures near the surface of the earth, occurring aat:300380466 aragonite as stalactites, in sediments, iron-ore deposits, and basic rocks. It is also commonly found in pearls, coral, and shells. It was used in antiquity for beads and other decorative artifacts. aat:300254874 aramid Synthetic fiber produced from long-chain polyamides, suitable for cable, rope, tape, textile, and webbing. aat:300136732 architectural bronze Bronze of very high copper content, formulated for color. Flat glass used for utilitarian purposes, although the term is sometimes used to describe what is known as stained glass. In modern times some is made in solid or aat:300010855 architectural glass hollow blocks to be used for building walls. Can be decorated by etching, sandblasting or other techniques. aat:300010670 architectural terracotta A hard-burnt, glazed or unglazed clay unit used in building construction, machine extruded or handmade. aat:300011341 argillaceous limestone Limestone containing 10 to 50 percent clay. aat:300011275 argillaceous rock Rock, especially limestone and sandstone, containing clay. aat:300011385 argillaceous sandstone Sandstone composed of clay minerals, especially sedimentary materials such as marl and shale; it emits a peculiar earthy odor when breathed upon. aat:300011276 argillite Compact argillaceous sedimentary rock that is cemented by silica. aat:300133261 argon Inert noble gas with symbol Ar and atomic number of 18, used in metalworking and as a filler for electric incandescent and fluorescent light bulbs. A starch obtained from the tubers of the Maranta arundinacea plant native to Florida, the West Indies and Central America. Arrowroot starch is used as a binder and aat:300130948 arrowroot (starch) adhesive. In the mid 1850s, arrowroot starch was used as a binder in salted photographic papers. It produced a bright image with a good density range and high resolution. aat:300213699 arsenic A grayish-white element with symbol As and atomic number 33, having a metallic luster, vaporizing when heated, and forming poisonous compounds. Synthetic arsenic disulfide first made in the 18th century as the counterpart to natural realgar. The synthetic variety was purer and less expensive, but is no longer used aat:300311458 arsenic orange because of its toxicity. aat:300386565 arsenopyrite A white or steel-gray mineral, iron arsenic sulfide, which occurs in crystalline rock and as the principal ore of arsenic. aat:300206140 art glass (material) Glass, especially types invented in the 19th century, that incorporated newly developed techniques for producing colors and surface textures. Asphalt mixture of 13-60 percent bitumens with finely pulverized mineral fillers, usually limestone. It differs from natural asphalt by the presence of paraffin and a aat:300012969 artificial asphalt greater content of petroleum oils. aat:300011160 asbestine Finely fibrous variety of talc used especially as a filler for rubber and paper and as an extender and white pigment in paint. A commercial term for any of several fibrous magnesium silicate minerals readily separable into thin, strong fiber that is flexible, noncombustible, heat resistant, and chemically inert; used in a wide variety of industrial products. It was used by the ancient Greeks, Egyptians, and Chinese as a fireproof material. In the 19th and early 20th centuries, asbestos was used for fireproofing and insulating houses: small asbestos fibers were mixed with binders and compressed into boards, paper, pipe aat:300011071 asbestos covering, ironing board covers, shingles, tiles, and sprayed onto ceilings. Long asbestos fibers were woven into fabrics for used in brake linings, heat-resistant shields, gloves, and fireproof garments and blankets. Health concerns have limited the use of asbestos since the early 1960s. In the U.S., it was declared a hazardous material in 1986. aat:300010367 asbestos-cement Fire-resistant, waterproofing material made by combining portland cement with asbestos fiber. aat:300011701 ashlar Small dimension stone with a flat faced surface, usually square or rectangular. aat:300010547 ashlar brick A brick whose face has been hacked to resemble roughly hacked stone. The dark, brownish-black bituminous resin that is found in natural deposits or is produced as a byproduct of oil refineries. It has consistencies varying from viscous liquid to glassy solid. It is composed of aliphatic, alicyclic, and polycyclic aromatic hydrocarbons. It is soluble in oils and waxes and can act as a plasticizer or a strengthener, depending on the hardness of the variety. Natural asphalt, which is believed to have been formed during an early stage in the breakdown of organic marine deposits into aat:300012966 asphalt (bituminous material) petroleum, characteristically contains minerals, while residual petroleum asphalt does not. Asphalt has been used since the 3rd millennium BCE for waterproofing; it is also used for road paving, roof coating, joint sealing, and a waterproof barrier in sandy soils. Ancient sources for asphalt were Egypt, the north end of the Dead Sea, the Is river northwest of Babylon, and the Greek island of Zante. Adhesive and binding material that is a preparation of refined asphalt and heavy petroleum oil, made by refining petroleum until there is no water or foreign maater in it, aat:300010368 asphalt cement except for the minerals naturally found in the asphalt. Asphalt cement contains less than one percent ash. Usually used for paving. A composite material consisting of gravel, sand, and stone that is bound together with asphalt; it is laid down in layers and compacted. It is commonly used in aat:300010739 asphalt concrete construction projects such as road surfaces, airports, and parking lots. The ingredients are mixed under high temperatures and kept heated until applied to a surface. Dark brown or black solid to semisolid material that is the organic, or hydrocarbon, portion of asphalt. It was used in ancient times as a sealant, for example in ancient aat:300375654 asphaltic bitumen Egypt. It is currently is used in hot-melt adhesives, coating, paints, sealants, roofing, and road coating. aat:300212378 asphaltite Any one of the naturally occurring black solid bitumens that are soluble in carbon disulphide and fuse above 230 degrees Fahrenheit. aat:300266161 asteroids Rocky bodies that are about 1,000 km or less in diameter and that orbit the Sun primarily between the orbits of Mars and Jupiter. A green mineral named in 1801 by D. de Fallizen for the Atacama Desert in Chile. It occurs naturally as copper oxychloride in oxidation zones of copper deposits in North aat:300404730 atacamite (mineral) America, Europe, Asia, and Australia, or as chloride corrosion on copper and bronze. The mineral has been used as a pigment on sculpture, manuscripts, maps, and frescoes. The gas and aerosol envelope that extends from the ocean, land, and ice-covered surface of a planet outward into space; used especially in reference to the earth where aat:300255945 atmosphere it is held by the force of gravity. Oxygen in its atomic form as it exists at altitudes over 12 miles above Earth's surface. It is the result of photo dissociation of molecular oxygen enabled by the ultraviolet aat:300387459 atomic oxygen radiation found in space. Atomic oxygen comprises 96% of low Earth orbit atmosphere. In conservation, an atmospheric atomic oxygen beam is effective in removing through oxidation organic materials that are typical of graffiti or other contaminant defacements which may occur to the surfaces of paintings. aat:300209716 aatapulgite A chain-laatice clay mineral, also a group name for lightweight fibrous clay minerals characterized by their bleaching and absorbent qualities. aat:300147976 augite Mineral occurring in igneous rocks such as basalt. Stainless steel containing up to 30% chromium and 20% nickel; used chiefly in aircraft and other transport equipment because of its high strength and corrosion aat:300010921 austenitic stainless steel resistance. A quartz mineral that contains shiny flecks of mica. Aventurine is usually green but can also be orange or reddish-brown. It is sometimes used as an inexpensive aat:300011154 aventurine (quartz) alternative to jade. Most aventurine comes from Russia, India, and Brazil. A synthetic imitation, "aventurine glass," is used for costume jewelry under the name "goldstone." Aventurine is also sometimes incorrectly called "Chinese jade" or "Indian jade." Synthetic imitation of aventurine quartz crystals. Goldstone is made by embedding metallic flakes in quartz glass. It is used in costume jewelry. It is a translucent glass aat:300206175 aventurine glass flecked with metallic particles to imitate the appearance of brownish aventurine quartz. aat:300010642 axed brick A brick that has been shaped with an ax and not trimmed when laid. aat:300311373 ayah kyauk The grass green variety of jadeite obtained from Myanmar. Earthenware tile of Spanish or Portuguese manufacture, painted and enameled in rich colors. They are typically large and used to decorate the exterior walls of buildings. aat:300010723 azulejo The term is probably of Arabic origin but its derivation is debated. A copper-based mineral, copper carbonate hydroxide, that is often used in jewelry ranging from very deep blue to pale blue. Azurite is often found in association with the aat:300266450 azurite (mineral) green mineral malachite, resulting from weathering and oxidation of copper sulfide. aat:300343501 babool gum An inferior type of gum arabic derived from various species of the Acacia genus. aat:300010529 backing brick A relatively low-quality brick used behind face brick or other masonry. aat:300010441 ball clay A kind of ceramic clay of exceptionally small particle size and, consequently, very good plasticity. Used to impart plasticity to other clay bodies. Fragrant myrrhlike oleoresin obtained from the small evergreen tree, Commiphora opobalsamum, native to the Middle East. Used in perfumes and medicines. Referred to aat:300375600 balm of Gilead in biblical Genesis as a healing balm; valued in medicine and perfume in ancient Greece and the Roman Empire. The term "balm of Gilead" has been incorrectly used to refer to "Canada balsam," which is derived from a North American tree. An oleoresinous exudate from coniferous trees, especially of the Pinus genus. Balsams have been used since antiquity for medicinal purposes and as sealers. The aat:300012891 balsam (resin) exudate is a soft, semi-liquid consisting of terpenes of resinous character and a large amount of essential oils. Upon distillation, a liquid portion, called turpentine, and a solid residue, called rosin, are produced. Balsams have been used in varnishes and paint mediums; however, they deteriorate easily unless a harder resin is mixed with aat:300311499 bambooware (porcelain ware) Bamboo- or cane-colored porcelain biscuit, invented by Wedgwood. For objects made from woven or carved bamboo, use "bamboo work (visual works)." aat:300010442 banco (clay) Shaped, beaten clay used for making granaries. Slate that is distinguished by the light colored stripes or ribbons running through it. It was prized as a material in bannerstones and other ancient American ceremonial aat:300011664 banded slate objects. When used in construction, it is known for being less durable than other slates because the ribbons are weaker than the surrounding dark areas. aat:300264904 barco Refers to a dark beige travertine; it is darker in color than Roman classic travertine. aat:300011498 bardiglio An Italian marble commonly having a dark gray or bluish ground traversed by veins and occurring in its principal varieties in the neighborhood of Carrara and Corsica. aat:300011500 bardiglio 'scuro A type of bardiglio marble that is saccharoidal and gray or bluish in color; it is considered inferior to bardiglio fiorito. aat:300011499 bardiglio fiorito A type of bardiglio marble in which the veining bears a resemblance to flowers. The most common barium mineral, barium sulfate (BaSO4), occurring in hydrothermal ore veins containing lead and silver, in sedimentary rocks such as limestone, in clay deposits formed by the weathering of limestone, in marine deposits, and in cavities in igneous rock in Spain, Germany, and in the southern Appalachian, central aat:300013788 barite states, and California in the United States. It commonly forms as large tubular crystals, as rosettelike aggregates of those crystals, or as divergent plates known as crested barite. It is abundant. Ground barite is used in oil and gas well drilling muds, in the preparation of barium compounds, as a body or filler for paper, cloth, and phonograph records, as a base for white pigment, and as an inert body in colored paints. A whitish, malleable, metallic element from the alkaline earth group, occurring primarily as a sulfate (barite) and less often as a carbonate (witherite). Salts of barium aat:300311585 barium are used as pigments in paints, ceramics, glass, plastics, and rubber, as fillers, as pesticides, and to produce the green color in fireworks. aat:300386849 barium aluminate A compound with mineral bonding properties used in aqueous solution for consolidation of mural paintings. aat:300266374 barium compounds Compounds consisting of the chemical element barium. Barium compound and fixative which, when used with ammonium carbonate solution, can repair the deterioration caused by calcium sulphate crystallization on fresco aat:300266375 barium hydroxide surfaces. A rare lead compound, a transparent to pale white mineral in the monoclinic system. It was first identified in the lead-antimony vein at the southwestern end of Bounds aat:300386566 barstowite Cliff, Cornwall by Cornish mineral collector Richard A. Barstow. It has also been found as a corrosion product on lead artifacts. aat:300011222 basalt (basic igneous rock) A dense, hard, dark brown-to-black volcanic igneous rock, consisting of feldspar and mafic minerals such as augite or olivine. Metal or alloy that is not resistant to oxidation and corrosion in moist air; base metals are thus distinguished from "noble metal." Base metals are also usually of aat:300241615 base metal minimum monetary value, and are thus commonly distinguished from "precious metal" as well. Igneous rocks as classified according to chemical or mineralogical parameters, having low silica and typically high iron - magnesium content; examples are gabbro and aat:300011221 basic igneous rock basalt. aat:300014535 basic liquid epoxy A commercially important liquid epoxy resin, diglycidyl ether of bisphenol-A, prepared by reaction of epichlorohydrin with bisphenol-A. aat:300233419 batch Mixture of the unmelted raw materials, such as sand and cullet, properly proportioned and ready for fusion into glass. A soft, aluminum-containing ore; it is an impure mineral that contains hydrous aluminum oxides and aluminum hydroxides. It is named for one location where it was aat:300387544 bauxite mined, Baux, France, near Arles. aat:300011679 beach cobble A cobble found on beaches that can be used for inexpensive paving or building. Variety of fossil resin, brown in color, having a high oxygen content. It is found in deposits in the Baltic and is characterized by being dense and polishing poorly. It had aat:300311360 beckerite previously been classified as being mineralogically distinct from common Baltic succinite on the basis of physical properties such as density and chemical properties such as saponification number, although more recent testing has found this to be untrue. Wax produced by many species of bees, containing around 10% hydrocarbons in addition to alcohols, faaty acids, and esters, with the primary component myricyl palmitate. The wax most commonly used by humans is from Apis mellifera. Beeswax is secreted by the worker bees to form honeycomb cells. The wax is prepared by melting the combs in hot water, then filtering out the resins, sugars, plant materials, and other impurities. The age, diet, location, and species of bee affects the color aat:300014588 beeswax and texture of the wax. Beeswaxes can be soft or brittle with colors ranging from light yellow to dark brown. The darker varieties are often bleached by exposure to light and air or with chemicals. Beeswax has been used as a protective coating, in etching, for candles, adhesives, paint binder, polish, in encaustic, leather dressing, cosmetics, and to modify paint. aat:300010958 bell metal Bronze used chiefly for casting large bells. Its standard composition is 78% copper and 22% tin but is varied to give varying tones. aat:300010461 bentonite A soft plastic light-colored clay formed by the chemical alteration of volcanic ash; it can swell to several times its original volume when placed in water. A dark, pleasant smelling oleoresin obtained from trees of the genus Styrax, including S. benzoin and S. officinalis, growing in Thailand, Malaysia, and Indonesia. Benzoin resin was used by the 16th century as a spirit varnish for paintings. It is also used as a plasticizer for varnishes and lacquers, a perfume, an antiseptic, and a aat:300012909 benzoin (resin) deodorizer. Benzoin resin is not the same as the chemical called "benzoin," which is a powder obtained from benzaldehyde. For a brown, sticky, aromatic resin obtained from trees of the genus Liquidambar, use "storax." Essential oil derived from the rind of the bergamot orange, Citrus bergamia, which is cultivated principally in Calabria, southern Italy. The aromatic oil is used in teas, aat:300386985 bergamot oil confectionery, and perfumery. aat:300011072 beryl A hexagonal mineral, which includes several varieties of gemstone such as emerald and aquamarine. A resin extracted from birch bark. It has been identified as a component of archaeological tars found in Austrian sites, demonstrating that the Iron Age tars were made aat:300380221 betulin from birch. A white marble from Cappadocia, Turkey that has light yellow veins over which there are hair lines of a darker shade of yellow. It can be so highly polished that it can aat:300011535 bianco e giallo create a reflection like a mirror; for this reason the emperor Domitian supposedly had a corridor lined with it. Little or none remains from antiquity. aat:300311589 bianco e nero antico (marble) The white and black variety of marble from Marmara Adasi, Turkey. aat:300054014 bidri Copper-zinc alloy of India, finished with a velvety-black color by a solution of copper sulfate. aat:300011501 bigio antico Marble, generally from North Africa, that is light and dark gray in large paaterns. aat:300011503 bigio e nero antico A dusty gray variety of marble from the island of Marmara Adasi, Turkey. aat:300011505 bigio e nero di francia Marble, generally from southern France, that is characterized by yellowish brown streaks and impure black and white waves. aat:300011507 bigio morato Marble, from the island of Melos on the Nile, that is dusty black in color with faint streaks and spots of gray. An alloy of silver mixed with an equal or greater amount of a base metal, usually copper. Alloy of gold or silver with a majority admixture of base metal, often copper or aat:300194590 billon tin. aat:300387550 bindheimite A secondary mineral found in the oxidized zones of antimony-bearing lead deposits. Moldable transparent plastic material made of compounds derived or synthesized from biological and/or palaeontological materials. Unlike traditional plastics, which are aat:300393229 bioplastics derived from petroleum, bioplastics are made from renewable resources and are biodegradable. aat:300209728 biotite Common rock-forming mineral of the mica group. aat:300011170 birthstone A precious stone associated with the specific month of a person's birth. Unglazed ceramic material that has been fired only once; generally producing a grainy texture; frequently used for modeling ornament or making small statues, dolls, or aat:300242297 biscuit (porcelain, material) vessels. Distinct from "parian (porcelain)," which is silky in texture and marblelike in appearance. Pure metallic element having as symbol Bi. Bismuth is brittle with a low melting point; a grayish-white lustrous metal oxidized by air. It is chiefly used in the arts as an aat:300379646 bismuth alloy, as in bronze, and is used ground as a pigment. aat:300010628 bitudobe A modern adaptation of sun-dried brick that contains a binder of emulsified asphalt. Any of various solid or semisolid mixtures of hydrocarbons that occur in nature or that are obtained as residues from the distillation of petroleum or coal. For the blackish aat:300012976 bitumen (material) hydrocarbon portion of asphalt, use "asphaltic bitumen." A relatively soft coal containing the tarlike substance asphaltic bitumen. Its carbon content is 60-80%, the rest composed of water, air, hydrogen, and sulfur. It is of higher quality than lignite coal but of poorer quality than anthracite. It was usually formed as a result of high pressure on lignite. It dark brown to black in color, commonly banded or layered. The major problem with burning of bituminous coal is air pollution. A relatively soft coal containing the tarlike substance asphaltic aat:300015143 bituminous coal bitumen. Its carbon content is 60-80%, the rest composed of water, air, hydrogen, and sulfur. It is of higher quality than lignite coal but of poorer quality than anthracite. It was usually formed as a result of high pressure on lignite. It dark brown to black in color, commonly banded or layered. The major problem with burning of bituminous coal is air pollution. General term for certain mineral inflammable substances that are native hydrocarbons, more or less oxygenated, whether liquid, semi-solid, or solid. Examples include aat:300012964 bituminous material naphtha, petroleum, asphalt. aat:300080058 black chalk Natural chalk containing carbon or shale and used for drawing especially since the Renaissance. aat:300011484 black marble Marble that is predominantly black in color. aat:300014295 black oil Linseed oil cooked at a high temperature with as much white lead or litharge as will combine with it. aat:300011657 black slate Slate that is predominantly black in color. Select, unfading, black slate of uniform color and thickness with all edges ground and accurately squared so that joints can be made tight, smooth, and on the same aat:300011649 blackboard slate plane. Beeswax, usually dark in color, that is treated by exposure to light and air or with chemicals to remove the color. For beeswax not treated for color uniformity, use aat:300014589 bleached beeswax "unbleached beeswax." aat:300411542 blister pearl Pearly excrescence of irregular shape found on the shell of a pearl oyster; may have one flaatened side. Semiprecious stone composed of dark green chalcedony with flecks of red jasper that were thought to resemble drops of blood. Bloodstones, when submerged in water, aat:300011138 bloodstone give a reddish reflection. They were occasionally used in ancient times as cylinder seals, during the Middle Ages for sculptures representing the flagellation of Christ, and currently as gemstones in jewelry. aat:300010832 blown glass Glassware shaped by blowing air through a blowpipe into a glob of molten glass. aat:300014273 blown oil A thickened oil obtained by blowing a faaty acid, such as linseed oil or fish oil; used in paint and varnish as a drying oil and in lubricant. A type of mold-blown glass blown in full-size molds that usually consist of three parts, but occasionally the term is used to describe glassware made in two-, four-, or aat:300233421 blown three-mold glass five-part molds. aat:300010539 blue brick A brick of high strength whose blue color results from firing in a kiln with a flame of low oxygen content. aat:300011658 blue slate Slate that has components of speculite and graphite in proportions that cause a bluish black color. aat:300014287 bodied oil A drying oil whose drying properties have been increased. aat:300014294 boiled oil Linseed oil prepared by heating to less than 600 F in a closed container to eliminate oxygenation. It dries quickly and creates a hard film. Originally a trademarked name for a hard and polishable plastic material made from albumen from blood or egg white mixed with hardwood sawdust and coloring. The mixture was steam-heated and poured into molds, where it cooled to form a hard, dense, glossy object. Patented by François Charles Lepage in France and England aat:300404195 bois durci 1855-1856, the invention was later bought by A. Latry, a manufacturer of desk wares such as inkwells and decorative boxes.The material was also used for combs, pipe stems, inkwells, and plaques, and medallions for furniture. aat:300230251 bole (clay) Soft, unctuous clays of various colors, used as pigments and in the ground for gold leaf. The rigid, calcareous material that is white in color and forms the skeleton of vertebrates; primarily composed of calcium hydroxyapatite with smaller amounts of calcium carbonate, calcium fluoride, magnesium phosphate, and ossein, a high molecular weight protein. Bones have a concentric structure with central lymphatic canals aat:300011798 bone (material) surrounded by a spongy lamellar region protected by a dense outer cortex. Bone has been carved and used since ancient times for many purposes, including fish-hooks, spear heads, needles, handles, and art objects. Bones were also burnt to produce bone black and boiled to produce bone glue. Bone can be distinguished from ivory by being generally whiter, more porous, and less dense. Material comprising hard paste porcelain modified by the addition of bone ash to the usual clay and feldspathic rock. It is characterized by being bright white in color. A patent was first taken out in the 1740s by Thomas Fry at Bow for the use of bone ash in china ware, but bone china in its present form was first introduced by Spode in aat:300233473 bone china (material) 1796. Softer than hard-paste porcelain, more durable and economical than soft-paste, it became the standard English porcelain body in the 19th century and is still used today. aat:300014819 bone glue Glue made from degraded or denatured collagen obtained from bones. aat:300010705 bonnet hip tile A tile that resembles a bonnet; used to cover the hip on a hip roof. Flat, cellular roofing tile having two parallel edges, one of which is convex and the other concave, so that a number may be fit together edge-to-edge between rafters, aat:300010680 book tile joists, or the like. A white or colorless crystalline mineral composed of hydrated sodium borate, used as a flux, cleansing agent, tanning agent, water softener, preservative, fungicide, as an alkaline ingredient in glass, ceramics, and glazes, in soldering, and as a source of boron. Borax is produced by the evaporation of water in shallow lakes. Borax was aat:300011077 borax used by the Egyptians for mummification, by the Romans for glassmaking, as a flux for soldering gold in 9th-century Arabia, in ceramic glazes in northern China in the 10th century, and in Venetian glass from the 13th century. aat:300187977 bordering wax Wax formed into an edge around a printing plate so that the plate may be bitten before immersion; used especially for extra-large plates. Non-metallic solid element, atomic number 5, symbol B, with several specialized uses, such as in alloy steels, in semiconductors, and in commercially valuable aat:300264228 boron compounds such as borax and boric acid. It is usually prepared as a brown powder, but when very pure it forms hard, shiny, dark crystals. aat:300010800 borosilicate glass Silicate glass containing at least five percent boric oxide and used in heat-resistant glassware. aat:300014361 borrow soil Soil borrowed from another location to be used in construction. aat:300400910 botallackite (mineral) An unstable copper trihydroxychloride isomer with a green or blue-green hue. Found in Cornwall, England, Austria, Germany, Greece, and the southwest United States. A gray and white marble that is similar in appearance to Formosa marble and is from the same region in Germany; it is, however, generally somewhat lighter in color aat:300011509 bougard marble than Formosa marble. aat:300011671 boulder The largest rock fragment recognized by sedimentologists, a boulder is a detached rock mass larger than a cobble, having a diameter greater than 256 mm (10 in.). aat:300379310 bowenite A type of serpentine that is hard, compact, and translucent, resembling nephrite. It was a favorite of Chinese carvers. aat:300010946 brass (alloy) Alloy of copper and zinc, usually with copper as the major alloying element and zinc up to 40% by weight. aat:300011425 breccia A coarse-grained dastic rock, composed of angular broken rock fragments held together by a mineral cement or a fine-grained matrix. A type of breccia marble, recognizable for the many chips of chalky white which go against the grain of the marble and look like wet paint. Its name may derive from its aat:300011454 breccia a semesanto resemblance to a paste of sugar plums or it may derive from 'Semo Sancus,' a Sabine divinity, to whom statues may have been carved out of this material. A breccia marble containing red, pink, white, or yellow fragments in a coral-colored matrix; it was notably used for the interior columns of the Temple of Mars Ultor in aat:300011453 breccia corallina Rome although few other specific examples are known and its ancient quarry has not been located. A breccia marble that is typically grayish violet with striking bright red or golden yellow streaks as well as oblong white, yellow, or red fragments. It originates from the aat:300011455 breccia di Settebasi island of Scyrus and is named for Septimius Bassus, who in antiquity had a villa sumptuously decorated with it on the Via Tusculana in Rome. Marble composed of angular fragments imbedded in a finer ground or paste; among the best known are the Egyptian breccia, many Numidian marbles, and the breccias aat:300011451 breccia marble of Gragnano and Seravezza, Italy. aat:300011456 breccia traccagnina A pink and brown breccia marble, the name of which derives from an old Italian name for a harlequin costume. aat:300011457 breche violette marble A coarse breccia marble of sharply angular red, pink, and white fragments in a dull red-brown matrix. aat:300010463 brick (clay material) Clay or clay products formed into a rectangular block and hardened by drying in the sun or firing in a kiln. aat:300010427 brick cement Waterproof cement used in masonry work. aat:300010466 brick slip A solid tile used to simulate brickwork. aat:300010467 brickbat Pieces of broken brick, especially those with one end of the brick left whole. aat:300206358 brilliant-cut glass Glass with very deep, complex, and polished cutting. aat:300010983 britannia metal A type of pewter that usually contains copper. Its color is silvery white with a bluish tinge, or with a yellowish tinge if the copper content is high. A dull yellow compact marble with irregular veins and blotches of dull terracotta red; it also sometimes contains patches of white crystalline calcite. Found in Catalonia in aat:300011542 brocatelle marble northern Spain and in Siena, Italy. A handsome shell marble from Tortosa, Spain, where it is still quarried. Its predominant color ranges from a reddish lilac to yellow, the color being dependent on the aat:300011475 broccatello quantity of embedded snails: the yellow represents the mollusk and the lilac represents the seabed in which it sank. Broccatello was used extensively as surface ornamentation in churches in Rome and Naples, Italy. aat:300011458 broccatellone A breccia marble consisting of cream-colored pebbles on a lilac ground tinged with yellow. An element with atomic number 35 and symbol Br belonging to the halogen family. It is the only nometallic element that is liquid at room temperature. Bromine is aat:300389668 bromine extracted from sea water by reaction with chlorine and is used in dyes, fumigants, and other applications. Refers to a broad range of alloys of copper, specifically any non-ferrous alloy of copper, tin, and zinc or other trace metals. Bronze was made before 3,000 BCE -- possibly as early as 10,000 BCE, although its common use in tools and decorative items is dated only in later artifacts. The proportions of copper and tin vary widely, from 70 to 95 percent copper in surviving ancient artifacts. Because of the copper base, bronze may be very malleable and easy to work. By the Middle Ages in Europe, aat:300010957 bronze (metal) it was recognized that using the metals in certain proportions could yield specific properties. Some modern bronzes contain no tin at all, substituting other metals such as aluminum, manganese, and even zinc. Historically, the term was used interchangeably with "laaten." U.S. standard bronze is composed of 90% copper, 7% tin and 3% zinc. Ancient bronze alloys sometimes contained up to 14% tin. aat:300183641 bronze powder Any metal, as a copper alloy or aluminum, in fine flake form used as a pigment to give the appearance of a metallic surface. aat:300011290 bryozoa limestone Fossiliferous limestone containing fossils of invertebrates of the phylum Bryozoa which are characterized by a branching, twiglike skeleton. aat:300380122 brèche d'Alep A particular type of breccia marble, composed of fragments of rocks of several different colors, found in Provence, France. aat:300262483 buhrstone Any of various siliceous, open-textured types of limestone or sandstone; uses include for millstones and as building material. aat:300010534 building brick (clay products) Brick made from natural clay and having no special surface treatment. aat:300014345 building sand Selected sand used for concrete, for mortar, for laying bricks, and for plastering. aat:300011700 building stone Any stone used for building. Refers to a type of glass characterized by central circular ridges around a pontil mark. It is a pane created from the central portion of a sheet of crown glass, which is aat:300263720 bull's eye glass created by spinning a bubble of glass on a rod and cutting one end so that the bubble opens into a large circular sheet. aat:300010886 bullet-resistant glass Glass, generally about 4 cm thick, made of several layers of laminated glass separated by layers of vinyl or plastic. aat:300194600 bullion Gold or silver considered in mass rather than in value, often in ingot or bar form. Variety of fossil resin found in deposits in Burma; usually red in color but may also be pale yellow, golden, or brown. It was used by the Chinese in the manufacture of aat:300311359 burmite art objects. aat:300014357 burnt daga Construction material consisting of daga, which is a coarse, granular, sandlike substance, that has been burnt to increase its durability and impermeability. A four carbon saturated alkane hydrocarbon that occurs naturally in petroleum. It is used in high performance liquid fuels for household and industrial purposes, as a aat:300013008 butane propellant in aerosols, and as a raw material for synthetic polymers. Gum derived from the tree Butea Monosperma native to parts of Southeast Asia and India. Used variously in cooking; as an astringent in medicine; and is valued for its aat:300387582 butea gum tannin content in leather working. aat:300014385 butyl rubber A synthetic rubber which is a copolymer of isobyutylene, and 1 to 3% isoprene. Thermoplastic made by the esterification of cellulose with acetic acid and butyric acid in the presence of a catalyst; particularly valued for coatings, insulation, varnish, aat:300133212 butyrate and lacquer. aat:300010741 béton (English, variety) Concrete consisting of lime, sand, and gravel. Pure metallic element having symbol Cd and atomic number 48; a silver white crystalline metal, very ductile, and which can be rolled or beaten into thin sheets; aat:300011018 cadmium (metal) resembles tin but is harder. Use also for this metal as processed and formed, usually in combination with other substances, to make objects and materials, including pigments. Refers to a type of glass that became popular in the 19th century. It is usually opaque and is characterized by a lime-yellow or lemon-yellow color that is caused by the aat:300263810 cadmium sulfide glass presence of cadmium sulfide in the glass mixture. Selenium is sometimes added to the mixture to create orange or bright red glass. It is not related to "sulphides (glass)," which is glass characterized by the insertion of a carved object into clear glass. A natural admixture mineral of zinc carbonate and hydrous zinc silicate. Because the two ores are very similar and often occur together, the name calamine was given to aat:300400565 calamine (natural mineral admixture) the mixture but also incorrectly used for the separate minerals. To differentiate the minerals, they were given new names of smithsonite (zinc carbonate) and hemimorphite (hydrous zinc silicate). The name was derived from the place name La Calamine (Kelmis), Belgium. Fossiliferous limestone composed of coral and shell and oolite particles or debris from erosion of older limestones. Calcarenites have been used as a building and aat:300379609 calcarenite ornamental stone, especially in the Apulia region of South Eastern Italy. Homogenous sandstone with a cement or matrix of calcium carbonate which binds together the quartz particles of which sandstone is mainly composed. It splits almost aat:300011392 calcareous sandstone equally well in both directions and is easily worked but disintegrates upon exposure. Pure calcareous sandstone is white or cream in color; colors are due to impurities: yellow and red colors are due to the presence of iron oxides; green from glauconite; and black from manganese dioxide. aat:300011078 calcite A common rock-forming mineral, usually white or gray, it is the chief constituent of limestone and most marble. A silvery white metal, with symbol Ca and atomic number 20, the fifth most abundant element in the earth's crust, occurring in many compounds. Its uses include as a aat:300264232 calcium nutritional supplement to assist the growth of bone and teeth, as a dehydrating agent for organic solvents, and to remove gases from molten metals prior to casting. aat:300212174 calcium carbonate A white crystalline powder occurring naturally chiefly as the minerals calcite and aragonite. Colorless crystal or soft, white, alkaline powder prepared by reacting calcium oxide (lime) with water in a process called slaking. It is used in paints, dehairing hide, aat:300011737 calcium hydroxide medicines, and in conservation for superficial protective treatments thanks to its conversion into calcium carbonate. A salt of oxalic acid, calcium oxalate can form naturally on calcareous stones as a reaction to oxalic acid excretions of mosses and lichens. In a conservation context, aat:300379564 calcium oxalate calcium oxalate is generally considered in its role as a form of bioterioration but its cultivation as a protective film for limestone surfaces has been investigated as well. Any of several forms of calcium oxide obtained from heating calcium carbonate (limestone, marble, chalk, and shells); when calcium carbonate is heated to about 500 C, carbon dioxide is driven off leaving anhydrous calcium oxide or quicklime. When quicklime is soaked in water, it is changed to calcium hydroxide or slaked lime. Slaked aat:300011736 calcium oxide lime that is dried and ground to a fine powder is called hydrated lime or lime hydrate. Lime will eventually harden and react with carbon dioxide to reform calcium carbonate. Lime is used in mortar, cement, stucco, glass, whitewash, putty, leather tanning, papermaking, and as a water-softening agent. Compound formed by interaction of free calcium and phosphate. Calcium phosphate is a component of bone and tooth enamel and the chief source of calcium in bovine aat:300379780 calcium phosphate milk. aat:300379928 calcium phytate Refers to the calcium salt of phytic acid. In conservation, used in a solution to inhibit iron gall corrosion on manuscripts. aat:300386422 calcium propionate A mold inhibiting calcium salt used as a food preservative. In conservation, used for reduction of acidity and fungi in aged paper documents. Any silicate of calcium as occurs crystallized in diopside and other minerals. Hydrated calcium silicate with inorganic fiber reinforcement is commonly molded into a high aat:300386591 calcium silicate temperature insulation material, a safe alternative to asbestos. Calcium silicates are also used in the manufacture of materials such as glass, porcelain, and cement, and as fillers for plastics and paper. A mineral found as efflorescence on some calcareous specimens and archaeological ceramics stored in oak museum cases. Its name alludes to its components: calcium, aat:300386583 calclacite chlorine, and acetate. aat:300011285 caliche Cemented deposits of calcium carbonate materials. Artificially produced, radioactive metallic chemical element with symbol Cf and 98 as atomic number. Californium has a few specialized uses as in neutron activation aat:300380331 californium analysis of metals in ancient coins, and in airport security full body scanning. aat:300181908 cameo glass Cased glass of two or more layers in contrasting colors. The outer layers are carved, cut, or engraved to produce a design which stands out from the background. aat:300013017 camphor (resin) The white resin of the species Cinnamomum camphora, used for hardening nitrocellulose plastic. Camphor is also in pharmaceuticals, disinfectants, and explosives. Yellowish-brown wax exuded from the leaves and stems of Euphorbia antisyphilitica, native to Mexico and the southwestern United States. It is hard, brittle, aromatic, opaque to translucent, and has little tack. Candelilla wax is obtained by boiling the leaves and stems in water and sulfuric acid. It is composed of hydrocarbons, with aat:300014608 candelilla wax smaller amounts of esters and triterpenoids. It is an all-purpose wax used for leather dressing, polishes, cements, Ebonite varnishes, candles, sealing wax, paper sizing, waterproofing, metal casting, and insect-proofing. Candelilla wax resembles carnauba wax but is less hard. Because it blends with other waxes and is less costly, candelilla wax is often used as an extender. aat:300211575 cane (glass) A slender rod of glass. A type of hydrogen-rich, sapropelic coal characterized by a dull black, sometimes waxy luster that lights easily and burns with a bright, smoky flame. Cannel coal consists of micrinites, macerals of the exinite group, and certain inorganic materials. Cannel coal usually occurs at the top or bottom of other coals, though it sometimes can be found as individual . It was probably formed in lakes and pools where floating spores, transported by wind and water, accumulated in mud mixed with plant debris. During the 19th century cannel coal was used in the manufacture of illuminating gas and as fireplace coal. A type of hydrogen-rich, sapropelic coal characterized aat:300015145 cannel coal by a dull black, sometimes waxy luster that lights easily and burns with a bright, smoky flame. Cannel coal consists of micrinites, macerals of the exinite group, and certain inorganic materials. Cannel coal usually occurs at the top or bottom of other coals, though it sometimes can be found as individual . It was probably formed in lakes and pools where floating spores, transported by wind and water, accumulated in mud mixed with plant debris. During the 19th century cannel coal was used in the manufacture of illuminating gas and as fireplace coal. The pure, milky, sticky, elastic, resinous juice obtained from various species of the tropical genera Hevea and Ficus. It coagulates on exposure to the air, becomes highly elastic, and is waterproof. Distinguished from "gutta-percha" in that caoutchouc must be heated longer to set. In the early 19th century, the name "caoutchouc" was also aat:300263583 caoutchouc (resin) used for a commercial rubber-based cement in which a small amount of the elastomer was dissolved in a solvent and mixed with mastic. Today, this material is called "latex." aat:300010531 capping brick Brick having special shapes for use in capping the exposed top of a wall. Any compound of carbon, hydrogen, and oxygen in which the last two elements occur in the same proportion as in water. Carbohydrates include monosaccharides (fructose, glucose), disaccharides (sucrose, maltose, lactose) and polysaccharides (starch, cellulose, gum, agar, carrageenan). They are manufactured by plants and aat:300264233 carbohydrate provide the major source of energy for animals and people. Simple carbohydrates, such as sugars, are water-soluble with a sweet taste. Starches and gums are composed of repeating saccharide groups. They swell in water to form a gel and can be hydrolyzed to obtain their sugar constituents. Cellulose is insoluble in water and organic solvents. Carbohydrates are used as paint binders, varnishes, adhesives, and sizing agents. Element that forms the framework for all tissues of plants and animals. Chemical symbol C and atomic number 6. Carbon may appear in many forms, including diamond, aat:300264720 carbon graphite, charcoal, carbon black, and fullerene. High quantities of carbon occur in coal, coke, oil, gasoline, and natural gas. Proteins such as hair, meat, and silk contain carbon and other elements. More than six and a half million compounds of the element carbon exist, including sugar, starch, and paper. Colorless gas (CO2) with a sharp odor; it is a minor component in the earth's atmosphere, does not support combustion, dissolves in water to form carbonic acid, is aat:300013018 carbon dioxide formed in animal respiration and in the decay or combustion of animal and vegetable maater, and is absorbed from the air by plants in photosynthesis. Carbon dioxide is used as a refrigerant and is found in carbonated beverages and fire extinguishers, among other uses. An odorless, colorless, tasteless, and highly poisonous gas produced by the incomplete combustion of carbon-containing materials. It is used in organic synthesis and aat:300013019 carbon monoxide metallurgy. Steel that does not have specified minimum content levels of alloying elements. The term can also refer to steel that does not have more than 0.40% copper or to steel aat:300010907 carbon steel that has maximum content levels of the following: manganese 1.65%, silicon 0.60%, and copper 0.60%. aat:300011344 carbonaceous limestone Limestone that is rich in carbon. aat:300011283 carbonate rock Any rock consisting chiefly of carbonate minerals such as calcite, dolomite, or siderite. aat:300264235 carbonyl Any member of a group of organic compounds, -COOH, in which a carbon atom is doubly bonded to an oxygen atom. Almandine that is cabochon-cut (a rounded, convex polished surface) and deep red in color. Its base is often hollowed to lighten its color. May display a four-rayed aat:300380390 carbuncle asterism (star-shaped), if rutile needles are included in the almandine. Very hard, yellowish vegetable wax exuded from the leaves of the Brazilian palm Copernicia prunifera, native to the arid regions of northeastern Brazil. The leaves are collected, dried, then beaten to remove the waxy surface coating. The yellowish wax is purified and bleached prior to marketing; it is available in several grades. Carnauba wax is harder than beeswax and melts at a higher temperature; it is used in compounds of wax and other material to impart hardness, a glossy finish, and aat:300014609 carnauba wax durability. Uses include floor waxes, car waxes, shoe polishes, leather finishes, carbon paper, other paper coatings, lubricants, metal casting, printing inks, varnishes, rubber coating, dental floss, coatings for food products such as candy, musical instrument polishes, and surfboard wax. Because of its hypoallergenic and emollient properties as well as its shine, carnauba wax is used in cosmetics and pharmaceuticals to coat tablets, thicken lipstick and mascara, deodorant, and various skin care preparations. aat:300133223 carnelian A translucent red or orange variety of chalcedony, containing iron impurities. It is often used for seals and signet rings. aat:300210969 carnival glass Pressed glass with an orange gold iridescence made with a colored spray rather than by the presence of metallic oxides. A coarse, pebbly, or gritty rock found in certain areas of southern and eastern England; it contains a great deal of iron oxide and is therefore always some shade of aat:300011434 carstone brown. It hardens upon exposure but it does not weather well and is not considered a good building stone. One of the standard alloys of brass, containing 70% copper and 30% zinc. It has high ductility and an aatractive yellow color, and is used for deep-drawn or spun articles aat:300010947 cartridge brass such as lamp bases, horns, and cornets. aat:300010833 cased glass Glass formed of two or more fused layers of different colored glass. A natural phosphorus-containing protein found in milk, composed of amino acids Casein curds form naturally as milk sours, but it is also precipitated by adding dilute hydrochloric acid to hot skim milk. The curds are collected, washed and dried to form a white to yellowish powder. The dried casein is insoluble in water and alcohol but is soluble in carbonates and other alkaline solutions. For use, casein is soaked overnight in a solution with a weak alkali (ammonium carbonate, borax, or lime) to form a aat:300011799 casein clear, viscous solution. Casein has been used as a glue and binder since earliest recorded periods. In the late 19th century, casein was made into a plastic by treatment with formaldehyde, used for small items such as buttons, beads, buckles, combs, cutlery handles, and knitting needles. They were often pigmented to simulate ivory, horn, or tortoiseshell. A beady starch obtained from the tuberous roots of the cassava plant, Manihot esculenta, native to tropical America. The roots are leached then dried and ground. The aat:300012960 cassava (starch) starch has irregularly shaped kernels; when heated with water it forms a thick stringy solution that gets thinner with heating time. It thickens only slightly on cooling to form a translucent gel. It is used for food, a thickening agent in cooking, laundry starch, and as adhesive for stamps, envelopes, labels, and plywood. A heavy, metallic, hard tin dioxide, chemical formula SnO2, that is the major ore of tin. It is colorless when pure, but brown or black when iron impurities are present. aat:300264236 cassiterite Commercially important quantities occur in placer deposits, but cassiterite also occurs in granite and pegmatites. An iron alloy containing about 2 to 4% carbon and 1 to 3% silicon, having a high compressive strength but low tensile strength. Cast iron is manufactured by melting scrap iron or pig iron in a cupola that is in contact with the coal fuel, then casting the molten iron into a mold. A large range of building and decorative items are made of aat:300011004 cast iron cast iron by pouring the molten metal into sand molds and then machining. It is inexpensive and easy to make. It was made in China by at least the 3rd century BCE; the technique for its production did not reach Europe until medieval times. Concrete that is deposited in liquid form in the place where it is required to harden as part of a structure; for concrete that is cast and cured in other than its final aat:300240021 cast-in-place concrete location, use "precast concrete." Viscous, clear to pale yellow non-volatile faaty oil obtained from the seeds of Ricinus communis or Palma Christi of the spurge family, having a nauseating taste. Used in aat:300014319 castor oil medicine as a purgative, and also in the production of synthetic resins, plastics, fibres, paints, varnishes, drying oils, and plasticizers. General term for a very pale yellow or straw-colored dammar from trees of the genus Hopea, considered one of the highest grades of dammar. It is no longer sold aat:300012927 cat's eye dammar commercially. Yellow in color and often sold in round balls, thus the name "cat's eye." General term for a very pale yellow or straw-colored dammar from trees of the genus Hopea, considered one of the highest grades of dammar. It is no longer sold commercially. Yellow in color and often sold in round balls, thus the name "cat's eye." aat:300136731 catalin A thermosetting plastic made of a cast phenol-formaldehyde resin and having high compressive strength and ready machinability. aat:300010443 catlinite A red indurated clay from the upper Missouri region historically used by Native Americans for tobacco pipes and other carvings. A soft, gray-green, iron silicate mineral that was first described in 1847 near Verona, Italy. It is a mica type mineral that has been found as a pigment in some Chinese aat:300311401 celadonite and Indian paintings. Transparent to translucent orthorhombic mineral, a member of the baryte group. It is colorless with faint shades of blue (alluded to by its name), red, white and other aat:300386592 celestine hues. Celestine occurs mainly in sedimentary rocks, especially dolomites and dolomitic limestones, and is mined for its strontium content. aat:300380496 celloidin Preparation of pyroxylin dissolved in ethanol-ether used in microscopy for embedding specimens. Glossy transparent material made from regenerated cellulose, typically in the form of thin sheets, usually moisture-proofed and sometimes dyed; impervious to dry aat:300248126 cellophane gases, grease, and bacteria, and used as packaging or wrapping for food and other merchandise, envelope windows, and bags for dialysis. A tough, highly flammable but not usually explosive, synthetic thermoplastic composed essentially of cellulose nitrate and camphor or another plasticizer. It was originally a trademark of Hoechst Celanese. It was marketed as a substitute for ivory, horn, amber, tortoiseshell for use in piano keys, dolls, buttons, combs, brushes, aat:300014447 celluloid (cellulosic) mirrors, collars, dental plates, and other small items. Tough, transparent sheets and strips of celluloid were also used for photographic and motion picture films as well as animation cels. Celluloid film was cast from a solution of cellulose nitrate with wood alcohol (methanol), amyl nitrate, camphor and fusel oil (amyl alcohol). A complex natural carbohydrate, or polysaccharide, composed of long, connected chains of glucose molecules, forming the primary component in the cell walls of plants. aat:300012861 cellulose (complex carbohydrate) Pure cellulose is an odorless, tasteless white powder. Cellulose exists in three forms: alpha, beta and gamma. Cellulose is used to manufacture paper and textiles, and as a raw material in rayon, cellophane, cellulose acetate, and celluloid. A tough, flammable, easily fabricated thermoplastic polymer composed of acetic acid ester of cellulose. Forms include white flakes or powder; it is used in a variety of products such as acetate fiber, lacquers, photographic film, magnetic tapes, lacquers, and transparent sheeting. The substance was first developed in 1865; in 1908 it aat:300014439 cellulose acetate was introduced as safety film by Eastman Kodak, replacing flammable cellulose nitrate film. As the cellulose acetate ages, the added plasticizers can migrate to the surface producing an oily film. aat:300138328 cellulose diacetate Compound used most frequently as a plastic in the production of motion picture film. A class of water-soluble polymers with a cellulose backbone and ether-containing substituents. Cellulose ethers are white bulky solids that form clear, hygroscopic films. aat:300014441 cellulose ether They are made by treating cellulose with concentrated sodium hydroxide followed by etherification with one or more reagents such as methyl chloride, ethyl chloride, ethylene oxide or propylene oxide. They are used as adhesives, poultices, consolidants, and coatings. aat:300130950 cellulose triacetate Fully esterified cellulose acetate containing three acetyl groups per glucose unit. aat:300014437 cellulosic Thermoplastic made from cellulose or a cellulose compound. Any of several finely powdered inorganic materials that can be mixed with water then dried to form a solid, durable mass, such as plaster, lime, pozzolan cement, and aat:300010362 cement (construction material) portland cement. It is used in construction as an ingredient of mortar and concrete. aat:300386423 cementite Extremely hard carbide of iron, a synthetic phase in technical iron alloys; in its naturally occurring form it is known as cohenite. Conglomerate rock composed of alluvial gravels and sands which is found in Lombardy, Italy. Ceppo has been used as building material, as well as for statues and carved aat:300389899 ceppo decorations, since Roman times. Refers to any of various hard, brittle, heat-resistant and corrosion-resistant materials made by shaping and then firing a nonmetallic mineral, such as clay, at a high aat:300235507 ceramic (material) temperature. Fired clay in various shapes and thicknesses and with a variety of uses, as for surface covering, drainage, or construction. For flat, solid, and relatively thin durable aat:300010678 ceramic tile material used primarily for surface covering, use "tile." aat:300256226 cerargyrite A very soft mineral, composed of silver chloride, ranging in color from a white to pale-yellow or gray. Ozorite that has been purified by boiling and alkali treatments. It is a white or slightly yellowish mineral wax that is similar to paraffin, but is harder and has a higher aat:300014602 ceresin melting point. Ceresin is composed of a wide range of long chain saturated hydrocarbons. It is used for candles, textile and paper sizing, floor polish, waterproofing, shoe polishes, leather coating, and as a substitute for beeswax in polishes and protective coatings of sculptures. A translucent, quartz usually with a waxy luster, having tiny microscopic crystals that are sometimes arranged in slender fibrous bands; occurring in various colors, aat:300011134 chalcedony usually red, blue, or green. A natural fine-grained, greenish-blue corrosion product associated with cuprite and atacamite observed on ancient Egyptian bronzes. The formation of chalconatronite aat:300380499 chalconatronite seems to have been due to the presence of hydrated sodium carbonates in the arid soils of certain parts of Egypt. A common, bright brass-yellow mineral with a metallic luster and greenish or purplish iridescence, constituting the most important ore of copper and composed of copper aat:300209729 chalcopyrite iron sulfide. Chalcopyrite is mined in North and South America and in Europe. aat:300011727 chalk A fine-grained limestone, or soft, earthy form of calcium carbonate; used chiefly in putty, crayons, paint, rubber products, linoleum, and as a pigment and abrasive. aat:300012868 cherry gum Gum from a cherry tree that is used as a binder for pigments, often as a substitute for gum arabic. Fine-grained, dense sedimentary rock consisting of interlocking crystals of quartz approximately 30 microns in diameter. Chert and its varieties, such as flint, are non- aat:300011141 chert gem varieties of cryptocrystalline-granular quartz. These stones chip very easily and thus may be fashioned into tools with a sharp edge; they are also used for building. aat:300014332 chika Any kind of earth, especially clay, that is mixed with water to make mortar in Ethiopia. Colorless, tough, protective natural substance composed of a nitrogen containing polysaccharide. Chitin is the principal component in seashells as well as the aat:300192976 chitin exoskeletons of crabs, lobsters, insects, and beetles. It is also found in the cell walls of some fungi, algae, and yeasts. Chitin is inelastic, thus growing arthropods must shed their exoskeletons periodically. Chitosan is the deacetylated form of chitin, the chief component in the exoskeletons of crustaceans, insects, and beetles. It is used in horticulture and agriculture as a biopesticide, and plant growth enhancer; and in medicine as a coagulant. As a sprayed coating, cyanoethylated chitosan is used to protect historic paper material. aat:300380051 chitosan Chitosan is also found as an organic component incorporated into polymer materials to form a self-healing coating which promises to render the painted surfaces it is applied to scratch-free. An element, symbol Cl and atomic number 17, that is at ordinary temperatures a greenish-yellow gas, toxic and corrosive to the eyes and respiratory system. It aat:300264246 chlorine becomes a liquid at -29 degrees Fahrenheit. It occurs in nature in great abundance in compounds, such as common salt. Free chlorine is used as a sterilizing agent, such as for water. Widely occurring monoclinic mineral, usually green in color, associated with and resembling mica but chemically consisting of hydrous silicate of aluminum, ferrous iron, aat:300011079 chlorite or magnesium. Any of several organic compounds composed of carbon, fluorine, chlorine, and hydrogen. Developed during the 1930s and manufactured under the trade name Freon, CFCs found wide application after World War II as aerosol-spray propellants, refrigerants, solvents, and foam-blowing agents. CFCs have been found to pose a serious aat:300155077 chlorofluorocarbon environmental threat, greatly contributing to ozone depletion. In the stratosphere, the CFC molecules are broken down by the action of solar ultraviolet radiation and release their constituent chlorine atoms. These then react with the ozone molecules, resulting in their removal. aat:300010918 chrome steel Any steel with chromium as the predominating element, the chromium making the steel hard and wear-resistant. aat:300010919 chrome-vanadium steel Any chromium steel containing a small amount of vanadium; valued for its combination of strength and ductility. Pure metallic element having symbol Cr and atomic number 24; an extremely hard, silvery white metal with a bluish tinge. Use also for the metal as processed and aat:300011019 chromium formed, usually in combination with other substances, to make various objects and materials, notably stainless steel, heat-resistant alloy, high-strength alloy steel, and for wear-resistant electroplating. aat:300010940 chromium alloy Alloy in which chromium is the principle element. Brownish-black crytals or powder, insoluble in water, synthesized by the oxidation of amorphous Cr(OH)3 with oxygen. Developed as rod-like particles for thin film aat:300417285 chromium dioxide deposition as magnetic recording material, and as a catalyst. Chromium dioxide is no longer widely used because of high production costs and toxicity. A hydrous silicate of copper having a green or sky-blue, a shining luster, often opal-like in texture, and used as a gemstone. It has been gathered or mined as a aat:300311390 chrysocolla (mineral) semiprecious stone since 3000 BCE. The translucent to opaque stone is typically greenish or sky-blue in its natural state, but appears true green when ground into a fine powder, which is used as a pigment. aat:300011142 chrysoprase An apple-green variety of chalcedony valued as a gem. A type of white, gray, or greenish serpentine that is characterized as being hard with a silky, fibrous structure. Chrysotile found in Cyprus and Afghanistan was used for aat:300209731 chrysotile beads, amulets, seals, and inlays; it was often misnamed as jade. It was the most common source of asbestos. aat:300010742 cinder concrete A lightweight concrete made with cinder as the coarse aggregate. A soft, dense, red, native ore composed of mercuric sulfide, found in deposits in veins near volcanic rocks or hot springs around the world. Cinnabar was mined in the Roman Empire for use as a pigment and for its mercury content; it has been the main source of mercury throughout the centuries. The toxic stone was also used for aat:300311452 cinnabar (mineral) decoration and a talisman in Mayan tombs, as a colorant in Chinese carved lacquerware, in ink used by high officials in the Byzantine Empire, and other applications. Cinnabar is chemically identical to synthetic red mercuric sulfide, which is called vermilion. A white marble variegated with green and gray due to layers of mica and mica-like minerals. It originates from the island of Euboea in the Aegean Sea and bears a aat:300011545 cipollino resemblance to the cross section of an onion, hence its name, which derives from the Italian word for onion (cipolla). The term is now often applied to any crystalline white marble with greenish mica, particularly the schistose varieties. aat:300209734 citrine The yellow variety of crystalline quartz, closely resembling topaz in color. Pale yellow, lemon-scented essential oil derived from the tropical lemongrass Cymbopogon nardus, native to South Asia. This oil is used in perfumes, soaps, and insect aat:300380315 citronella oil repellents. Naturally occurring sediments that are produced by chemical actions resulting during the weathering of rocks. It is often the term applied to all earths that form a paste aat:300010439 clay with water and harden when heated. aat:300209715 clay mineral Any mineral that occurs as minute sheetlike or fibrous crystals in clay; it is a hydrated aluminosilicate having a layered crystal structure. aat:300011282 clay shale A shale composed wholly or chiefly of clay material which becomes clay after weathering. aat:300010599 clinker brick Very hard-burnt brick whose shape is distorted, owing to nearly complete vitrification; used for paving. aat:300010471 closer The last brick, block, stone, or tile laid in a horizontal course; may be either a complete unit or one trimmed at the site. Refers to a type of glass in which colored glass is mixed with white glass, to create an opalescent effect that resembles clouds. It is often used to create decorative aat:300263719 cloudy glass vessels. It is similar in appearance to "reamy glass" and to "Clutha glass," which means "cloudy glass." Carbon-rich material that most often occurs in stratified sedimentary deposits. It is one of the most important of the primary fossil fuels. It is characterized by being aat:300015149 coal solid, hard, opaque, black, or blackish, found in seams or strata in the earth, and largely used as fuel; it consists of carbonized vegetable maater deposited in former epochs of the world's history. Black viscous liquid with a naphthalene odor obtained by the distillation of bituminous coal. It can be separated into several fractions: gasoline, oil, creosote, and pitch. aat:300012992 coal tar Coal tar is used in the manufacture of plastics, aniline dyes, for waterproofing, paints, roofing, roads, and as a pesticide. aat:300380500 coal-tar epoxy A thermosetting resin resulting from the carbonization of bituminous coal. It is used as protective coating in many applications, including for marbles and stones. aat:300010735 cob (clay mixture material) Building material comprising a mixture of straw, gravel, and unburnt clay, especially used in the construction of walls, known as cob walls. The metallic element having the symbol Co and atomic number 27; it is a hard, ductile, white metal, resembling nickel but with a bluish instead of a yellow tinge. Cobalt was first identified by Georg Brandt of Sweden in 1735. It has an abundance of 0.001-0.002% in the earth's crust and is found in the minerals smaltite, cobaltite, aat:300221155 cobalt (mineral) chloanthite, linnaetite, and erythrite. Metallic cobalt is added to alloys to increase hardness at high temperatures. It is also ferromagnetic. Cobalt oxides and salts are usually blue and they are used as pigments in paints, glass, and ceramic glazes aat:300212176 cobalt glass Glass to which cobalt oxide has been added in order to produce a very strong blue color. A rock fragment, rounded or otherwise abraded, with a diameter between 64 and 256 mm, being larger than a pebble and smaller than a boulder. The term can also aat:300011677 cobble refer more specifically to a rounded stone suitable for use in paving or other construction. aat:300391195 coconut oil Semisolid fat oil derived from fresh coconuts, often used in the production of cosmetics and candles. aat:300380446 cod-liver oil Yellow oil derived from the Atlantic Cod and related fishes; a rich source of vitamins A and D used in medicine as a treatment for rickets. aat:300242158 coin silver Silver of the fineness legalized for coins; 90% fine in the United States, 50% fine in Great Britain since 1920. The dark, porous, carbonized residue left after the destructive distillation of bituminous coal, petroleum or coal tar pitch. Coal can be converted to coke by heating it in an airless oven to drive off all volatile components. Coke was once made in large quantities as a byproduct when coal was burnt to produce methane. Coke is useful in aat:300264249 coke (bituminous) metallurgy because it burns hotter than coal; it is used primarily as a fuel or as a reducing agent in the iron and steel industry, primarily in blast furnaces. The process for using coke in smelting was developed in the 17th century. In the 18th and 19th centuries coke aided in the expansion of the cast iron and steel production. Coke can also be converted to graphite. aat:300014275 cold-pressed oil Any vegetable oil that has been extracted from seeds or nuts by pressing them without the aid of heat. The fibrous, extracellular matrix protein in skin, muscles, tendons, ligaments, and bone. Collagen is composed of repeating units of glycine-proline-hydroxyproline that form linear polypeptide chains; three chains are then twisted and interlocked with hydrogen bonding to form a rigid helix structure. Collagen-containing materials, such aat:300192948 collagen as hides, bones and fish, have been used to make animal glues since ancient times. Collagen will irreversibly hydrolyze, or denature, in hot water, forming a water- soluble gelatin. aat:300127347 collodion Cellulose nitrate in a mixture of 60% ether and 40% alcohol for making fiber and film. aat:300010743 colloidal concrete Concrete in which the aggregate is bound by a grout that has the ability to retain dispersed solid particles in suspension. aat:300206572 combination inorganic/organic animal materialAnimal material, such as shell and bone, that is made out of both inorganic and organic material. aat:300206579 combination inorganic/organic material Material that is comprised of both organic and inorganic elements. An extraterrestrial body consisting of a frozen mass and rock debris that travels around the Sun in a highly elliptical orbit; it generally developes a diffuse gaseous aat:300266158 comets envelope and a long luminous tail when near the Sun. aat:300010481 compass brick A wedge-shaped brick used in arch or circular construction. aat:300014627 composite material Material formed, either intentionally or through natural processes, from more than one constituent material, each with separate physical or chemical makeup. Refers to various aggregate materials formed artificially from two or more substances, such as whiting, resin, and size used for modeling ornament in the late 18th aat:300237906 composition (material) century, or plaster of Paris, sawdust, bran, and glue used for dollmaking, or plastic cement-based mortars used in construction. aat:300210304 conch (shell) The spiral shell of gastropods, often blown as sounding horns. A hard, strong construction material comprising a mixture of sand, gravel, crushed rock, or other aggregate, held together, typically by a hardened paste of cement and/or lime. Several types of aggregate are used such as crushed stone, slag, cinders or gravel. Ancient Romans developed pozzolan cement about the 3rd century BCE. Modern concretes use various cements such as portland or hydraulic. Concrete is durable and relatively inexpensive, used for foundations, bridges, dams, walls, and aat:300010737 concrete highways. Concrete is strong in compression but weak in tension so it is often reinforced with steel bars or wire netting. Once a concrete mixture is stirred with water and poured into a mold, it is allowed to cure slowly over about a week. Stresses, such as vibration, freezing, and rapid drying, will diminish the strength and durability of the concrete. As it ages, concrete is subject to erosion, spalling, and pollution. Poor mixing can cause erosion. Spalling can be due to freeze-thaw cycles of moisture and ice, salt crystallization, or corrosion of steel reinforcements. Acid rain can deplete the natural alkaline reserve of fresh concrete. Rock characterized by, consisting of, or producing concretions; concretions are hard, compact aggregates of mineral maater, subspherical or irregular in shape, formed by precipitation from water solution around a nucleus, such as a shell or bone, in a sedimentary or pyroclastic rock. Concretions are generally different from the rock in aat:300011420 concretionary stone which they occur, and represent a concentration of some minor constituent of that rock. Concretionary stones include flint, chert, and nodules of impure limestone which sometimes occur in clay. The shell of various marine snails of the genus Conus and family Conidae, typically straight-sided with tapering body whorl, low spire, and narrow opening, and of vivid aat:300261859 cone shell colors and eccentric markings; it is valued as a material for bracelets, disks, and other ornament. Elastic sedimentary rock composed of rounded fragments varying from small pebbles to large boulders in a cement of calcareous material, iron oxide, silica, or hardened aat:300011430 conglomerate clay. A viscous, oleoresin obtained from South American deciduous trees of the genus Copaifera, native to the Amazon valley and banks of the Orinoco river. The volatile oil and resin contain one or more of the followings acids: illuric, metacopaivic, copaivic, and oxycopaivic. Copaiba balsam was brought to Europe in the 17th century for aat:300012898 copaiba balsam medicinal use; in the mid-19th century it was used with ethanol vapor as a varnish cleaner for oil paintings with blanched and cracked surfaces, and in the early 20th century as a glossy additive in paint media, although use has been discontinued because it produced damaging long-term effects. Copaiba balsam is currently used to make tracing and photographic papers. General term for a variety of hard, natural resins obtained directly from various tropical trees of the genera Hymenaea and Agathis. Copal is a characterized as a hard, translucent odoriferous resinous substance in an intermediate stage of polymerization and hardening between gummy resins and amber. Copals contain communic acids, communol, resene, and volatile oil. They range in color from colorless to a bright yellow-brown. The term was first applied to the substance obtained from Mexico; but aat:300012910 copal copal is now procured also from Brazil, the West Indies, West Africa, Mozambique and Zanzibar, Madagascar, India, Manila, New Caledonia, and New Zealand. Copal from East Africa is most highly valued, particularly the partially fossilized varieties. Copal is used as incense, flavoring, medicines, and in making varnish, lacquer, adhesive, and coatings. Pure metallic element having the symbol Cu and atomic number 29; a reddish brown, ductile metal that is present in the earth's crust, occurring as a native metal and as ores of sulfide, sulfate and carbonate (azurite, malachite, etc.). It was the first metal used by humans, probably from about 8000 BCE, in the regions of Mesopotamia and India. By about 3800 BCE copper was made into bronze for weapons and knives. Today, copper is one of the most widely used metals because it has high electrical aat:300011020 copper (metal) and thermal conductivity, can be easily fabricated, is ductile and polishes well. In moist air, copper forms a protective green film of basic carbonate. Metallic copper combines well with other metals to form alloys, most commonly brass and bronze. Copper and its alloys are used for wire, electrical devices, pipes, cooking vessels, ammunition, ornamental trim, roofing, grillwork, coins, musical instruments, jewelry, and sculptures. aat:300010942 copper alloy Alloy in which copper is the principle element. Yellowish-brown powder that absorbs moisture from the air to form green crystals soluble in water. Copper chloride is used as a fixative in dyeing and printing fabrics, as aat:300380465 copper chloride a wood preservative, and in refining of copper, gold, and silver. The hydrolysis and oxidation of copper chloride is responsible for the destructive formation of bronze disease. aat:300411561 copper leaf Refers to very thin hammered or rolled copper sheets (typically about 0.1 micrometers) used for decoration or finishing. Finely granulated copper with numerous metallurgical applications produced by various techniques such as electrolysis, atomization, hydroscopy. Each method of aat:300389997 copper powder manufacture yields a powder with its own inherent characteristics. aat:300206374 copper ruby glass Glass with a red color due to the presence of copper. A sulfate of copper, blue crystals in hydrous form, white when dehydrated. Copper sulfate is used as a preservative for wood, leather and paper; as a mordant and dye aat:300380504 copper sulfate for textiles; as a biocide, and for a wide range of other purposes. Broadly refers to any sulfide of copper, more specifically to the blackish crystalline sulfide CuS used in textile dyeing and as a black pigment in ancient painting. The aat:300380030 copper sulfide presence of copper sulfide on the surface of ancient bronze artifacts has generated much debate over whether it should be seen as symptomatic of copper corrosion or as an intentional patination technique. aat:300391391 copper sulfite A sulfite of copper. Uses include in herbicides applied to water to kill plants, but they are toxic to fish and other water animals. aat:300241444 copper-aluminum alloy An alloy that consists of half copper and half aluminum; marketed as a form of master alloy that is used for making aluminum alloys. Alloy of copper and beryllium containing usually not more than 3% beryllium. The alloy has a bronzelike, crystalline structure and is unsurpassed in its ability to aat:300133739 copper-beryllium alloy withstand fatigue, wear, and corrosion and in its electrical conductivity at high temperatures. aat:300010951 copper-nickel alloy The term used for the 75-25 and 50-50 cupronickel slabs, ingots, and shot used for adding nickel to brasses. aat:300010953 copper-silicon alloy Copper alloy containing silicon, either in small or larger amounts depending on the class, used for electrical wires due to its strength and resistance to corrosion. aat:300379448 coprolites Fossilized fecal material; indirect evidence of prehistoric life, particularly as pertains to ancient diet. A fossiliferous limestone composed of coarse shells or shell fragments which is loosely cemented by an infiltration of carbonate of lime; its name derives from the aat:300011305 coquina Spanish word for 'cockleshell.' Coquina is a detrital rock because it is formed from debris and is distinguished from coquinoid limestone which is formed in situ and is composed of shell material in a fine-grained matrix. aat:300011800 coral (material) Hard material consisting of calcium carbonate derived from the skeletal deposits of certain marine animals. aat:300011291 coral limestone Fossiliferous limestone composed of fragments of corals. Edible oil obtained from corn kernels, valued for its transparent flavor and light colour. It is used in a variety of edible and inedible products including cosmetics. Edible aat:300014316 corn oil oil obtained from corn kernels, valued for its transparent flavor and light colour. It is used in a variety of edible and inedible products including cosmetics. Starch derived from the endosperm of the corn kernel, separated from glutens and fibrous particles by sieving, wet grinding, and wash flotation. Heated with water it aat:300386593 cornstarch forms a viscous medium which thickens into an opaque gel with cooling. Cornstarch is used as a thickener in liquid based foods. aat:300380246 corrugated iron Structural sheet of iron or steel, usually galvanized for weather resistance, shaped in alternating ridges and grooves; used as roofing, siding, and the like. aat:300011080 corundum A very hard crystalline mineral made of aluminum oxide, used chiefly as an abrasive. The name applied to a number of Italian marbles, generally containing various hues and paaterns of red and brown although other colors such as white and purple are aat:300011548 cottanello often present. The modern species are coarse and often considered unaatractive; the ancient Romans quarried cottanello of superior quality about forty miles from Rome in the Sabine hills, near the town after which the stone is named. Vegetable oil made from the cotton plant, and popular as a food oil, such as in salad oils and margarine. Cottonseed oil also has a wide range of industrial uses, such as aat:300014312 cottonseed oil an ingredient in soaps and paint oils. The tiles that bridge the open joint between rows of tiles in a roof. For example, in ancient Greek architecture, the roof tile (imbrex) of terracotta or marble, usually aat:300162681 cover tile semicircular (Laconian) or triangular (Corinthian) in section, bridged the open joint between two rows of flat tiles or pantiles (tegulae). Shell of any of numerous marine gastropod mollusks of a family widely distributed in warm seas; beautifully polished, often brightly colored, and much used for aat:300011834 cowrie shell ornament or as money. Refers to a type of decorative glass that was invented in Venice during the 16th century. It is characterized by a surface that appears frosted or resembles cracked ice. It aat:300206380 crackle glass is produced either by plunging a gather of blown glass into a tub of water and then quickly reheating it, or by rolling the hot glass on a metal or clay surface covered with glass fragments that adhere to the gather, and then blowing the form. aat:300010700 crest tile Tile which fits like a saddle on the ridge of a roof, forming a crest. Fossiliferous limestone composed almost entirely of the fossil skeletal parts of crinoids, marine invertebrates of the phylum Echinodermata; crinoidal limestone is aat:300011298 crinoidal limestone particularly plentiful in North America. General term for Venetian glass often yellow or smoky gray in color unless formulated with the decolorizing agent manganese, which gives the glass the appearance of aat:300206392 cristallo rock crystal. aat:300380284 cristobalite Along with quartz and tridymite, one of the three principal forms of silica. It is a high temperature form of quartz found naturally formed in volcanic rock. A mineral consisting of lead chromate that occurs in the oxidized zone of lead mineral veins. It is compositionally identical to the pigment chrome yellow but only aat:300386594 crocoite secondarily related. The element chromium was found in this rare secondary mineral in 1787 and became the basis for the pigment which was subsequently produced synthetically. Yellow-brown poisonous oil derived from the seeds of the tree Croton tiglium native to India and Sri Lanka. Originally used as a purgative and as a substitute for castor aat:300014313 croton oil oil, it is now thought too dangerous for medicinal purposes. Flat pane glass made by blowing a bubble of glass, transferring it from a blow-pipe to a rod, cutting it open, then rapidly rotating it until, by centrifugal force, it is spread aat:300010838 crown glass into a flat disk. Can be either small individual panes with so-called bulls-eyes in the centers or large disks that are annealed and cut into pieces. Crown glass is thin and brilliant with a slight convexity and concentric wavy lines. Known to the ancient Romans throughout the Empire; found in windows of medieval cathedrals. Refers to hard cast steel made by various techniques, all of which involve heating of materials in crucibles. Modern equipment, such as the electric arc furnace, has aat:300380000 crucible steel made these methods obsolete. aat:300011681 crushed stone Rock, often granite, limestone, or trap rock, that is quarried, crushed, and graded and then used for making concrete, railway ballast, and road making. Fine, high quality, heavy, decorative glass made with fine white sand, at least 24% lead oxide, and small amounts of potash and niter. It is clear, colorless, highly aat:300010814 crystal (lead glass) refractive glass that is heavy and has greater than twice the density of standard borate glass. It was developed in England in 1676; often used for high quality chandelier prisms and fine stemware. Refers to cut crystal glass in which a decorative ceramic object is embedded, usually a medallion or cameo that has been carved into a white porcellaneous, heat- aat:300263809 crystallo ceramie resistant material. A Bohemian invention of the 18th century, the technique was taken up in Paris but only became popular through English glassmakers in 18th- and 19th-century Europe. For glass characterized by a particular yellow or red color, use "cadmium sulphide glass." aat:300206418 cullet Scrap glass intended for reuse or recycling. Alloy of copper, nickel, iron, and manganese in which copper is dominant. Cupronickel is the metal of choice for contemporary coins, and is also used for condenser aat:300194685 cupronickel plates and heat exchangers. aat:300380305 cuprorivaite A glassy blue mineral, named for its copper content and its similarity to rivaite, that is a component of the artificial inorganic pigment, Egyptian blue. Cuprous sulfide occurs in the form of black powder or lumps and is found as the mineral chalcocite. Large quantities of the compound are obtained by heating cupric aat:300264251 cuprous sulfide sulfide (CuS) in a stream ofhydrogen. Cuprous sulfide is insoluble in water but soluble in ammonium hydroxide and nitric acid. Its applications include use in solar cells, luminous paints, electrodes, and certain varieties of solidlubricants. aat:300011713 curbing Blocks or slabs of stone or concrete set on edge, creating an upward projection that is used as a curb; may be straight or curved. aat:300014314 curcas oil Yellow oil derived from the kernels of seeds of Jatropha curcas, native to Central America. This oil is used in cooking, soap, and as a strong purgative. aat:300206355 cut glass Glassware with facets, grooves, and depressions produced by cutting with a rotating wheel of metal or stone. aat:300375656 cutback asphalt Asphalt mixture that includes and additive to liquify the material for easier blending and applicaiton. aat:300010489 cutter (brick) In masonry, a soft brick sometimes used for facing because of the ease with which it can be cut or rubbed smooth. aat:300014270 cutting oil An oil or oily preparation used on cutting tools or on work being machined to aid in the cutting action. Thermoplastic polymer that, in its liquid form, consists of monomers of cyanoacrylate molecules. In the form of an acrylic resin it rapidly polymerises in the presence of aat:300403961 cyanoacrylate water; commonly used as a fast-setting, strong adhesive. Mass concrete in which large stones, each weighing 100 lb. (45.4 kg) or more, are embedded when the concrete is laid. The stones, called pudding stones or plums, are aat:300010744 cyclopean concrete typically less than 6 in. (15 cm) apart and farther than 8 in. (20 cm) away from any exposed surface. Flat pane glass characterized by straight ripples. Is made by an an ancient technique of blowing a large glass bubble and swinging it on a blow-pipe to form a long bottle, then cutting off both hemispherical ends. The resulting cylinder is then cut lengthwise and reheated after which it is flaatened by a wooden plane or by being allowed to aat:300010840 cylinder glass sink to a flat state. Traditionally, it was characterized by a great variability of texture, color, and thickness, though it is more regular when produced by modern methods. Cylinder glass largely replaced crown glass when the process of making it was mechanized. aat:300011181 dacite An extrusive acid igneous rock that is sometimes partly glassy and is composed of plagioclase and quartz with biotite, hornblende, or pyroxene. aat:300014356 daga (soil) Coarse, granular, sandlike substance that consists chiefly of clay, made into a mortar used in African building construction. Any of various resins obtained from various trees of the genera Shorea, Agathis, or Hopea, growing in the East Indies, New Guinea, and New Zealand. It is obtained by aat:300012922 dammar (resin) tapping trees or, more rarely, from fossilized specimens from the ground. The gum varies in color from clear to pale yellow, while the fossilized form is grey-brown. Dammar is used as a glazing or clouding agent in cooking, as incense, for caulking ships, and as varnish, especially as a picture varnish. Monoclinic crystalline mineral with a combined salt of sodium sulfate and sodium nitrate. Darapskite is found naturally in nitrate ores and in limestone caves. It is more aat:300380328 darapskite rarely found as a strong saline efflorescence on surfaces of walls and buildings. A carbonate of sodium and aluminum found as a low-temperature hydrothermal mineral in shale. It crystallizes in the orthorhombic crystal system. It is not mined for aat:300380365 dawsonite ore. aat:300210319 deionized water Water from which dissolved ions have been removed by passing the water through cationic and anionic ion exchange. aat:300379287 demantoid Bright green variety of andradite having a brilliant luster. Intensely hard calcareous substance covering the dentin, that is, part or all of the crown of the tooth in mammals. Enamel, when mature, consists predominantly of aat:300191879 dental enamel (material) apatite crystals containing calcium and phosphate. Enamel is the hardest tissue of the body; it is not living and contains no nerves. The thickness and density of enamel vary over the surface of the tooth. Material comprising the primary, bone-like structure of a tooth. Dentin is hard calcareous material, with less porosity and less organic maater than bone. It is generally aat:300191881 dentin (material) covered with a protective enamel layer. Layers of dentin cover animal teeth (whale, hippopotamus, boar, etc.) and tusks (ivory, elephant, walrus, etc.). Pressed glass made in the 1920s by automatic machines in factories in the American mid-west; it is thought to reflect the austerity of postwar life. Some paaterns are aat:300211734 depression glass reminiscent of 19th-century designs while others incorporate the sharp corners and precise lines of Art Deco styles. A fine-grained, compact, crystalline granular rock, consisting essentially of augite and a triclinic feldspar, with chloritic maater in varying amount, being an altered form aat:300011226 diabase of basalt. aat:300311167 diaminophenyl oxydiazole A bluish fluorochrome used to stain specimens and for other purposes. aat:300011084 diamond (mineral) A highly transparent and exceedingly hard mineral of carbon; it is the hardest known substance. aat:300206419 dichromatic glass Glass which appears to be a different color when viewed in transmitted or reflected light; often achieved by the addition of colloidal gold to the glass batch. aat:300070045 dimension stone Stone finished to a specific size and weight and squared to specific dimensions and thickness. A green, calcium magnesium silicate mineral sometimes used as a gemstone; a pyroxene-type mineral with short, monoclinic crystals. The transparent to translucent aat:300380508 diopside crystals have either a square or octagonal cross section. The color of diopside crystals ranges from light to dark green. Powdered diopside is used as a maating agent in ceramic glazes. A hard, coarse-grain, black-and-white speckled, granite-like rock composed of plagioclase feldspar mixed with hornblende, biotite, and augite, sometimes with small aat:300011214 diorite amounts of orthoclase or quartz. Diorite was valued by the Egyptians and Sumerians for statuary and is presently used in building construction. aat:300011777 distilled water Waters from which impurities, such as dissolved salts and collodial particles have been removed by one or more chemical processes. aat:300311591 dolerite A mineral allied to basalt, containing feldspar (labradorite) and augite. aat:300209942 dolomite (mineral) A common rock-forming mineral. A white, medium-grain marble composed of greater than 90% calcium magnesium carbonate. Dolomitic marbles were quarried in Cape Vathy on Thasos from antiquity aat:300380134 dolomitic marble to about the 5th century CE. A type of limestone whose calcium carbonate content approaches 45%; employed as a flux in melting iron, as a lining for basic steel furnaces, for the production of aat:300011348 dolostone magnesium metal, for filtering, and as a construction stone. aat:300010829 double strength window glass Sheet glass having a thickness of between 0.118 inches (3.00 mm) and 0.113 inches (3.38 mm). A transparent, resinous exudation, red in color, derived from several plants in 4 genera, having in common the primary red coloring component dracorubin. Dragon's blood is available as red sticks, cakes, or as a powder, and was traded as early as Roman times. It is used medicinally as an astringent, as a red colorant in medieval aat:300012929 dragon's blood (resin) manuscript illuminations, to stain varnishes for violins, as a colorant for plaster, marble, and paints, and as a resist in photoengraving to protect zinc plates from acid. The red color is fugitive when exposed to light and air, but may be partially protected by a resin film layer. aat:300010688 drain tile Ceramic tile, usually in short-length sections, used for constructing water drains. aat:300010844 drawn glass Glass that is made by continuous drawing of the molten glass by a series of rolls on automatic machinery. aat:300411611 dredge peat Peat excavated by dredging, this is often a mixture of different types of peat, and has a higher efficiency than dry cut peat. aat:300070050 dressed stone Dimension stone with a smooth exposed face. aat:300011778 drinking water Water that is safe or suitable to drink. aat:300379851 dry ice Solid carbon dioxide; used as a refrigerant. In the conservation science dry ice is sometimes used for cryogenic sandblasting of objects. aat:300014286 drying oil Any oil that will solidify to a tough, leathery film when spread out in thin layers, either alone or with the assistance of a drier. aat:300011005 ductile iron A type of cast iron that is similar to steel in both structure and some properties; it is often used for machine parts. An alloy consisting of 95.5 parts of aluminum to 3 parts of copper, 1 of manganese, and 0.5 of magnesium that after age-hardening is comparable in strength and aat:300010939 duralumin hardness to soft steel. aat:300011734 earth (soil) Refers to soil in the context of building materials. In ancient Greek architecture, the flat tile or pantile with a decorative nosing used on the eaves (with antefixes) as a substitute for the sima (terracotta or marble gutter aat:300162676 eaves tile of a building). In modern construction, tile, usually shorter or plainer than other roofing tile, used in the first course of tile along the eaves of a building. Class of dense metamorphic rocks consisting of red-brown garnet and green pyroxene omphacite; with trace amounts of jadeite, diopside, almandine, pyrope, grossular, aat:300380509 eclogite and rarely, diamond. Type of porcelain material comprising a relatively high proportion of clay to china stone, and usually produced in China or Europe. It is characterized by having extremely aat:300263307 eggshell porcelain (material) thin and fine, even translucent walls, and is typically white in color, thus resembling the shell of a bird's egg. aat:300010973 eighteen-carat gold Gold which has 18 parts of gold to six parts of alloying metal. A synthetic polymer with elastic properties similar to natural rubber that can recover its original size after repeated extensions to more than twice its initial length. aat:300014379 elastomer Examples of elastomers are polybutadiene, styrene-butadiene rubber, nitrile rubber, and butyl rubber. aat:300010965 electrum The natural alloy of silver and gold. Under the Egyptian name of Asem, it was believed to be an elementary metal until the Romans made it as an alloy. A soft, sticky, fragrant resin derived from trees of the family Burseraceae. Elemi is used in lacquer, lithographic inks, textile coatings, paper coatings, perfume bases, and aat:300012930 elemi (resin) waterproofing. It has been used as a plasticizer in varnishes, but the components responsible for its initial malleability (mono- and sesquiterpenoids) evaporate and it eventually hardens to a brittle film. The term was imprecisely used in the 17th and 18th centuries to describe many oleoresin mixtures. aat:300011239 elvan A type of quartz porphyry, local to Cornwall, England, which is usually light gray in color with a hint of buff; often used for ashlar because of its fine texture. A brilliant grass-green variety of beryl, highly prized as a gemstone. The name comes indirectly from the Greek "smaragdos," referring to a number of stones having little in common except a green color. The emerald in the the Bible was probably a garnet. However, ancient societies did also value the genuine emerald, which came from Upper Egypt as early as 2000 BCE. Greek emerald miners worked for Alexander the Great and Cleopatra. The physical properties of emerald are essentially the aat:300011074 emerald (mineral) same as those of beryl, with only moderate light refractive and dispersive powers, meaning that cut stones display little brilliancy or fire. The gems are instead valued for their magnificent color, which is probably caused by small amounts of chromium. The stone loses colour when strongly heated. Synthetic emerald was successfully produced in the 1930s, and today is produced by a either a molten-flux process or a hydrothermal method crystal growing process. Synthetic crystals appear very similar to natural emerald crystals. A gray-to-black impure variety of corundum which contains magnetite and hematite and is used as an abrasive. The stone is crushed and graded and used to make aat:300011081 emery emery paper, emery cloth, and emery wheels. An emulsion of asphalt cement and water, that contains a small amount of emulsifying agent. The amount of asphalt in emulsion will depend upon the grade and type, aat:300012985 emulsified asphalt but is typically 55-65% by volume. Uses include surfacing floors, painting pipes, and waterproofing concrete walls. aat:300410342 encaustic tile Ceramic tile having a decorative paatern that is not applied by glaze, but by using multiple color clays. aat:300010655 end-cut brick Brick having the end surfaces wire-cut. aat:300010536 engineering brick Brick having the nominal dimensions 3 1/5 in. by 4 in. by 8 in. (8.13 cm by 10.16 cm by 20.36 cm). aat:300011085 enstatite A mineral of the pyroxene group consisting of magnesium silicate varying in color from grayish white to olive green and brown. aat:300212647 enzyme One of a group of complex organic substances formed in the living cells of plants and animals; it is a necessary catalyst for the chemical reactions of biological aat:300014380 epichlorohydrin elastomer An ethylene-propylene elastomer noted for resistance to oils, ozone, weathering and heat. aat:300011086 epidote A yellowish green mineral consisting of a silicate of calcium, aluminum, and iron and occurring massive or in grains, columns, and monoclinic crystal. aat:300014533 epoxy resin Type of synthetic resin used to produce adhesive that sets by chemical reaction, rather than through loss of solvent and coalescence. Hydrous magnesium sulfate mineral usually found as a crust, efflorescence, or tiny crystals on mine and cave walls. Neutralized and purified, epsomite is sold as epsom aat:300380513 epsomite salts. A secondary mineral produced by the surface oxidation of primary cobalt. Erythrite is a violet to peach red arsenate once used as a pigment in paints, glass, and aat:300380514 erythrite ceramics; replaced for these purposes by its synthetic form, cobaltous arsenate. aat:300311402 eskolaite Mineral used to create chromium oxide pigment. aat:300014259 essential oil Aromatic oil found in uncombined form in various parts of plants and employed for flavoring, perfume, disenfectant, and medicine. A modified natural resin made from rosin that has been esterified by heating with a polyhydric alcohol, such as glycerol. Ester gum contains the glyceryl, methyl, and ethyl esters of rosin acids. Ester gum is lighter in color than rosin and have a higher softening point but lower acid number. It is not used in artist paints or varnishes although they have been tried for wax-resin linings. It is used instead of copal, dammar, or kauri in making enamels, paints, nitrocellulose lacquers, and tung oil aat:300012953 ester gum mixtures. A modified natural resin made from rosin that has been esterified by heating with a polyhydric alcohol, such as glycerol. Ester gum contains the glyceryl, methyl, and ethyl esters of rosin acids. Ester gum is lighter in color than rosin and have a higher softening point but lower acid number. It is not used in artist paints or varnishes although they have been tried for wax-resin linings. It is used instead of copal, dammar, or kauri in making enamels, paints, nitrocellulose lacquers, and tung oil mixtures. aat:300014442 ethyl cellulose A colorless, odorless ester of cellulose resulting from the reaction of ethyl chloride and cellulose; forms a durable alkali-resistant coating. Colorless liquid used, for example, as a source of colloidal silica in heat-resistant and acid-resistant coatings, as a protective coating for industrial buildings and castings, aat:300183770 ethyl silicate as a consolidant for stone, and as a bonding agent. aat:300014381 ethylene-propylene elastomer A commercially produced rubber with high chemical resistance and tear strength. aat:300251539 ethylene-vinyl acetate A thermoplastic copolymer used to improve adhesion properties of hot-melt and pressure sensitive adhesives, and for conversion coatings. A mineral composed of aluminum sulfate and hydrous basic calcium often formed by the reaction of sulfates and concrete or mortar. Ettringite crystal formation induces aat:300379946 ettringite sulfate decay in the cement paste matrix. Conservation interventions seek to remove ettringite or limit its aatack. Yellow essential oil with a camphor-like odor derived from the dry leaves of various species of eucalyptus tree. This oil is used in medicine, in perfumery, in leather aat:300380314 eucalyptus oil conditioning, and in other applications. Cement which when mixed with water forms a paste that tends to increase in volume after setting to a significantly greater degree than portland cement paste does; aat:300010428 expanding cement used to compensate for volume decrease due to shrinkage or to induce tensile stress in reinforcement. aat:300010777 expansive concrete Concrete made with expansive cement in order to reduce or control changes in volume during the curing stage. Plastics formed in an extrusion process, in which a molten polymer is passed from an extruder head and blown into a bubble of uniform film that is then molded, often aat:300014578 extrusion blown plastic into food packaging such as bottles for liquid. Igneous rock solidified on or near the surface after being ejected explosively or extruded as lava, as contrasted with intrusive rock; characteristically finely crystalline or aat:300011246 extrusive rock glassy. aat:300010540 face brick The better quality of brick such as is used on exposed parts of a building, especially those parts which are prominent in view. A composite material consisting of a body of sintered quartz coupled with an alkaline glaze surface, and used for decorating beads, amulets, figurines, and other small aat:300265183 faience (composite material) objects. It was invented in Mesopotamia or Iran ca. 4500 BCE, and produced through the mid-7th century CE. aat:300010724 faience tile Glazed or unglazed ceramic tile which shows characteristic variations in the face, edges, and glaze that give a handcrafted, non-mechanical, decorative effect. An ester of a long-chain faaty acid (such as stearic acid or palmitic acid), of plant or animal origin, that is that is nonvolatile, insoluble in water, oily or greasy to the touch, and solid at room temperature. Chemically, fats are identical to animal and vegetable oils, consisting primarily of glycerides, which are esters formed by the reaction of three molecules of faaty acids with one molecule of glycerol. Pure fats are colorless, odorless, tasteless and will float on water. Examples of natural fats are butter, lard and tallow. Fats may be hydrolyzed with an alkali to form soap in a process called saponification. Fats are also used in leather tannage, paints, and protective aat:300013023 fat coatings. An ester of a long-chain faaty acid (such as stearic acid or palmitic acid), of plant or animal origin, that is that is nonvolatile, insoluble in water, oily or greasy to the touch, and solid at room temperature. Chemically, fats are identical to animal and vegetable oils, consisting primarily of glycerides, which are esters formed by the reaction of three molecules of faaty acids with one molecule of glycerol. Pure fats are colorless, odorless, tasteless and will float on water. Examples of natural fats are butter, lard and tallow. Fats may be hydrolyzed with an alkali to form soap in a process called saponification. Fats are also used in leather tannage, paints, and protective coatings. aat:300011747 fat lime Quicklime having a good spread, used to fill voids as it is applied in a finish coat. Vitreous green iron silicate mineral, a member of the olivine group, named for the type locality, Fayal Island, Azores. The brittle stone was also produced synthetically as aat:300380515 fayalite a component of slag separated in smelting at ancient iron working furnaces. Refers to a type of glass made in Europe in the 16th and 17th centuries using the techniques and styles that had been perfected in Venice, Italy, the name being French aat:300263807 façon de Venise for "Venetian fashion." It was produced in areas outside Venice, including other parts of Italy, France, Spain, Britain, Germany, and the Netherlands, and it evolved various local stylistic and technical traits over time. General name for a large group of aluminum silicate minerals, usually white or flesh-red in color, occurring in crystals or in crystalline masses. Feldspars are divided into three primary groups: potassium aluminum silicates (orthoclase, microcline), sodium aluminum silicates (albite, anorthoclase), and calcium aluminum silicates aat:300011087 feldspar (anorthite). A few of the feldspars are found as gemstones such as moonstone, sunstone, and Amazon stone, but most are found in mineral structures, such as granite and diorite. They are used in the production of clays, ceramics, glass, concrete, abrasives, for cleaning, as a flux in ceramics, glazes, and glass, in fertilizer, and in granular roofing material. aat:300011396 feldspathic sandstone A sandstone containing 10 to 25% feldspar that is intermediate between a quartz sandstone and an arkosic sandstone. aat:300209739 feldspathoid Comparatively rare rock-forming mineral related to feldspar but containing less silica. aat:300011182 felsite A general term applied to light-colored, aphanitic acid igneous rock, composed mainly of feldspar and quartz and which may or may not contain phenocrysts. aat:300183772 ferric chloride Material used as an ingredient of mordants in the production of etchings rather than nitric acid due to its ability to produce more selectively vertical lines. aat:300380175 ferrous sulfide Monosulfide of iron found in nature as pyrrhotite and troilite. It is synthesized to use in generating hydrogen sulfide. aat:300011353 ferruginous limestone Argillaceous limestone that is red or rusty in color due to the presence of ferric oxide, the quantity of which may be quite small. aat:300011398 ferruginous sandstone Sandstone with reddish-brown stains caused by the rock's iron content. aat:300265786 fibro Cement and asbestos sheeting, used primarily in Australia to build cheap housing. aat:300010745 fibro-concrete Concrete containing fibers of such materials as glass, asbestos, wood, steel and plastic in order to reduce weight and increase tensile strength. Insoluble, white, fibrous protein comprising the filaments of raw silk, secreted along with sericin by the insect. Unlike wool, silk is composed mainly of non-sulfur aat:300192961 fibroin containing amino acids. The primary amino acids, glycine, alanine and serine, are contained in dense, highly crystalline regions of the fiber. The amorphous regions are composed of tryosine, tryptophane, histidine and phenylalanine. aat:300189659 fibrous composite Composite material made of fiber embedded in a matrix, as in some types of reinforced plastic. aat:300014924 fibrous plaster Plaster reinforced with fiber (as manila hemp or sisal) or provided with a cloth backing and used chiefly as sheeting, cornice molding, and cover strips. aat:300011684 fieldstone Loose stone found on the ground or in the soil. aat:300010857 figured glass Generally, glass used in architecture that is cut, embossed, sandblasted, or otherwise embellished. Plastics with additives applied to their formulation, usually adhesion promoters combined with particulate filler for reinforcing molding compounds, or fibers for aat:300014574 filled plastic reinforcing composite materials. aat:300242137 fine silver Silver metal assayed at better than 99.9% pure. aat:300010994 fine solder Soft solder of eutectic composition, possessing the lowest melting point of any type of solder; constituted in proportions of 60% tin and 40% lead. aat:300011549 fiore di Persico Variegated marble, of various shades of red, pink, and purple on a white ground-mass, quarried in ancient times principally at Epirus in Turkey. aat:300011551 fiorto marble Variegated marble of light chocolate brown and white, from Italy. aat:300010551 fire brick Bricks made of refractory ceramic material which will resist high temperatures; used to line furnaces, fireplaces, and chimneys. aat:300010586 fired brick A frequently used building brick, composed of clays or shales (and sometimes other materials), which has been fired to hardness in a kiln. aat:300014821 fish glue Glue made from the degraded collagen from fish skins and wastes. Also glue made from the swim bladders of fish, a tissue composed entirely of collagen. aat:300014290 fish oil Oil obtained from fish and marine animals. aat:300011687 flagstone Refers to large flat sections of slate used for paving and also bluestone cut for this purpose. Refers to a type of glass characterized by two or more layers of color, usually a thin layer or "flash" of colored glass layered on a clear or light-colored glass. It is created by dipping a small blob of dark glass into a pot of light-colored glass, and then blowing the blob into a bubble in which the distinct layers are formed. It is used to make aat:300263715 flashed glass stained glass windows, valued over "pot-metal glass" for certain effects, because the thinner layer of color allows more light to pass through the window, while the saturated color of pot-metal glass results in a darker interior. aat:300010659 fletton Type of brick made by a semi-dry process; originally named for the Oxford clay found near Fletton, England, which was often used in the London area. aat:300011143 flint (rock) The dark gray or black variety of chert. A brilliant lustrous glass made from a composition of lead oxide, sand, and alkali. It is often used in lenses and prisms because of its high index of refraction. This term is aat:300010802 flint glass sometimes used to refer more generally to "crystal (lead glass)." Sheet glass made by floating a ribbon of hot glass on a bath of heated liquid, usually molten tin. The process was developed in 1959 by Pilkington Brothers and is now aat:300010846 float glass the world's principal method of manufacturing good quality sheet glass which is clear, flat, with parallel and fire polished sides. aat:300010555 floor brick Smooth, dense brick which is highly resistant to abrasion; used for finished floor surfaces. aat:300014346 flooring sand Floor covering comprising loose sand. aat:300379942 fluoride Any compound joining fluorine to another element or to an organic group. Multi-colored transparent or translucent material containing calcium fluoride, commonly occurring in massive crystalline cube form with perfect octahedral cleavage, used aat:300011095 fluorite as flux, as a source of fluoride compound, and in the preparation of opalescent and opaque glass, vitreous enamel, and a purple pigment. aat:300389663 fluoro rubber Fluorocarbon elastomer-based synthetic rubber. aat:300014384 fluorocarbon elastomer Elastomer which is highest in resistance to oxidation, chemicals, oil, solvent, and heat; typical applications are brake seals, O rings, diaphragms, and hose. aat:300014449 fluoroplastic Type of plastic characterized by resistance to aggressive environments, including extremes of weather, and temperatures ranging from near 0 to 260 degrees Celsius. aat:300014407 fluorosilicone elastomer Elastomer with a high degree of solvent resistance and excellent low-temperature capabilities created by the addition of fluorine into a polyalkylsilsiloxane system. Light spongy rubber made by mechanically whipping air into the rubber latex prior to curing. It is used for maatresses, cushions, and insulation. Foam rubber turns aat:300014562 foam rubber yellow and becomes powdery when exposed to sunlight. Lightweight, laminated panels, typically made with a polystyrene layer between two coated papers. Acid-free foam boards are used for maating and mounting works of aat:300403965 foamboard art. aat:300133118 foamed concrete A very light, cellular concrete made by adding a prepared foam or by generating gas within the unhardened mixture. aat:300010764 foamed slag concrete Slag concrete to which a chemical foaming agent has been added, resulting in a lightweight slag concrete full of air holes. Thin sheet metal used chiefly for wrapping, insulation, electrical applications, and as an ornamental surface treatment. For extremely thin sheet metal used exclusively aat:300160106 foil (metal by form) for applied decoration, use "leaf (metal)." Bottoms of glass cups or bowls decorated with designs in engraved gold leaf backed by a protective layer of fused, sometimes tinted, glass; they were first made during aat:300261949 fondi d'oro the Roman Empire from the third to the early fifth centuries. Refers to glass that was originally manufactured in the forest regions of France and Germany in the Middle Ages. It is usually greenish, yellowish, or brownish in color, aat:300264532 forest glass and the glass is typically rather thick, simple in form, mold blown, and decorated with trailing and prunts. It is characterized by the alkali ingredient having been provided by potash from the ashes of burnt beechwod, fern (bracken), or other woods. aat:300260756 forest marble A marble of argillaceous limestone containing dark coloring maater so distributed as to resemble forests or landscapes. A flammable, colorless gas with a strong, suffocating odor; first synthesized in 1859, but it occurs naturally in coal and wood smoke, as an outdoor air pollutant in large aat:300013020 formaldehyde cities, and found in indoor environments from items such as new particle board, freshly laid carpet, foam, adhesives, insulation, and new fabrics. Formaldehyde is a powerful reducing agent reacts with many materials on contact. Aqueous formaldehyde solution containing 37% by weight of formaldehyde. In conservation it has been used as a fluid preserving medium, and, as an aerosol and aat:300386603 formalin fumigant, to treat algae on stone at sites such as the Lascaux caves. Formerly a brand name, now in common usage. A natural resin, such as amber and some copals, that originated from prehistoric coniferous trees that are now extinct. Fossil resins are generally dug from the ground or aat:300012933 fossil resin stream beds. aat:300011288 fossiliferous limestone Limestone that contains fossils. Remains, impressions, or traces of humans, animals, or plants of past geological ages that have been preserved in the earth's crust. The complex of data recorded in aat:300247919 fossils fossils worldwide--known as the fossil record--is the primary source of information about the history of life on Earth. Only a small fraction of ancient organisms are preserved as fossils, and usually only organisms that have a solid and resistant skeleton are readily preserved. aat:300014349 foundry sand Any sand employed for making molds for casting metal, but especially refers to refractory sand that has binding qualities. aat:300010972 fourteen-carat gold Gold alloy containing 14 parts gold to 10 parts alloying metal. aat:300386604 fragipan Dense subsurface soil layer that restricts water flow and root penetration. Aromatic gum resin containing a volatile oil that was valued since ancient times in worship, as a medicine, and as an incense resin. It is obtained from the Boswellia aat:300380405 frankincense (gum resin) sacra trees and others. It contains resins (mostly triterpenoids), gums, volatiles oils (pinene, dipentene), and bassorin. It is usually found in the form of hard yellow grains. aat:300233425 free-blown glass Refers to glass blown and shaped with a blowpipe and hand tools and without the use of a mold. aat:300011688 freestone Stone, as sandstone, that may be cut freely in any direction without fracture or splitting. aat:300162526 fresh water (water by property) Water that does not contain a large amount of salt, as in ponds, lakes or streams. aat:300191908 freshwater pearl The pearl from freshwater mollusks. Pulverized material made from flux, sand or other refractory that has been fused with heat but not fully vitrified; often used in making glazes and may contain a coloring aat:300343495 frit ingredient which will give the glaze coloring throughout. aat:300210312 fuller's earth Clay possessing a high absorptive capacity; it is extensively used as an absorbent in refining and decolorizing oil and fat. aat:300014454 furan Thermoplastic or resin used for bonding brick and tile. A hollow brick used for furring or lining the inside face of a wall; usually the size of an ordinary brick and grooved or scored on the face to afford a key for plastering; it aat:300010556 furring brick carries no superimposed load. aat:300011230 gabbro Igneous rock similar to diorite, predominantly composed of ferromagnetic minerals with crystals visible to the eye; has the same mineral composition as basalt. aat:300249795 gadolinium gallium garnet Synthetic garnet that if pure, is colorless and can be made to simulate a diamond. aat:300266177 galena A principal ore of lead; lead sulfide (PbS). Often contains silver. The thick, resinous exudation from the species Pinus pinaster of southern Europe, especially France. Galipot is similar to Venice turpentine (a balsam) and can be aat:300012938 galipot distilled to produce oil of turpentine. aat:300400673 gallium Chemical element with symbol Ga and atomic number 31. A silvery, soft metallic poor metal, it is used primarily as an agent to make low-melting alloys. Steel coated with a thin layer of zinc to prevent corrosion. The application may be effected by electroplating or spraying the steel with molten zinc, or by coating the aat:300386605 galvanized steel heated steel with zinc powder. Translucent golden-colored resin composed of a yellow resinous component and a clear water-soluble gum, produced by several trees of the genus Garcinia native to India, Thailand, Cambodia, Vietnam, and Sri Lanka. Gamboge was used as a yellow pigment as early as the 8th century in Asia and Japan. It was regularly imported to aat:300012939 gamboge (resin and pigment) Europe in the 17th century. It is marketed in the form of dull, brownish-yellow cakes or lumps that, when powdered, have a rich golden color. The carbohydrate gum acts as a natural binder. Gamboge is used as a transparent colorant in glazes, varnishes, and watercolors. The yellow color fades when exposed to light or ozone. In some cases it has recovered its color when placed in the dark. aat:300011624 ganister A natural refractory mineral used for furnace lining; in compact form it was used for furnace hearths. A general name for a type of mineral varying in color and hardness, including trisilicates of aluminum, magnesium, calcium, iron, manganese, vanadium, chromium, and aat:300011097 garnet (mineral) sometimes sodium and titanium. Used for coating abrasive paper and cloth, for bearing pivots in watches, for electronics, and the finer specimens as gemstone. aat:300013003 gasoline A colorless, liquid hydrocarbon obtained in the fractional distillation of petroleum which is used chiefly as a motor fuel but also as a solvent. aat:300238444 gather (glass) A glob of molten glass before it is tooled or fully shaped. aat:300010644 gauged brick Brick that has been ground or otherwise produced to accurate dimensions. A water-soluble, tasteless colloidal form of processed collagen obtained from bones, hooves or skins and used as a dispersing agent, sizing medium, adhesive, or coating aat:300011812 gelatin for photographic films, and stabilizer for foodstuffs and pharmaceutical preparations. Is high in molecular weight after processing, as opposed to more vigorously processed collagen which results in animal glue. Precious or semiprecious stone that can be cut, polished, or otherwise dressed for use as gems; distinguished from "gems," which are made of gemstone that has been aat:300201964 gemstone worked or other material such as pearl. A planar product manufactured from polymeric material used with soil, rock, earth, or any other geotechnical engineering related material, as an integral part of a man- aat:300178912 geosynthetic made product, structure, or system. Any permeable textile used with foundation, soil, rock, earth, or any other geotechnical engineering related material, as an integral part of a man-made product, aat:300178913 geotextile structure, or system. Semi-metallic element having symbol Ge and atomic number 32. A silvery gray metalloid, germanium occurs in sulfide ores and is used as a semiconductor, in alloys, aat:300380222 germanium and in the manufacture of infrared transmitting glass. aat:300011555 giallo tigrato A marble characterized by its cloudy mixture of pure white, pale brown, lilac gray, and pink on a yellow ground; it originates from Corinth. A thin layer of gold or other metal that has been applied as a decorative surface finish, whether the metal was applied as a thin leaf, by electroplating, or as a thin paint aat:300379350 gilding (material) layer. Examples of gilding include that applications on paintings, furniture, frames, sculptures, and the edges of pages of books. A variety of natural asphalt having a black color, brilliant luster, brittle consistency, and conchoidal fractures. It is found only in the Uinta Mountains of Utah. The term "gilsonite" was originally a registered trademark in the late 19th century. It is used in black varnishes, lacquers, baking enamels, japans, linoleum, floor tile, and paving aat:300012979 gilsonite where it increases resistance to acids, alkalis, and water. In the early 19th century, gilsonite was often mixed with mica, asbestos, gums, or resins to produce electrical components. It is also the first solid hydrocarbon to be converted to gasoline. aat:300010864 glare-reducing glass Glass whose chemical composition has been altered to produce a glass capable of absorbing a portion of the solar energy that reaches it. An amorphous, inorganic substance made by fusing silica (silicon dioxide) with a basic oxide; generally transparent but often translucent or opaque. Its characteristic properties are its hardness and rigidity at ordinary temperatures, its capacity for plastic working at elevated temperatures, and its resistance to weathering and to most aat:300010797 glass (material) chemicals except hydrofluoric acid. Used for both utilitarian and decorative purposes, it can be formed into various shapes, colored or decorated. Glass originated as a glaze in Mesopotamia in about 3500 BCE and the first objects made wholly of glass date to about 2500 BCE. aat:300010398 glass reinforced cement Cement reinforced with alkali-resistant glass fibers. Composite material consisting of a thermosetting plastic resin reinforced by glass in fibrous form. To refer to the reinforcing agent itself rather than the composite, use aat:300126977 glass reinforced plastic "fiberglass." aat:300014351 glass sand Sand employed in glassmaking. aat:300010821 glass wool A glass fiber, .001 inches in diameter. aat:300241926 glassmaking mixtures Combinations of material used for glass fabrication. A dull green mica mineral composed of hydrated potassium iron silicate, that -- unlike other micas -- usually occurs as pelletlike grains in marine environments and is aat:300311425 glauconite sometimes called "green sand." It is formed from the alteration of iron-bearing silicates by ocean water and organisms, is found along the Atlantic coast of the North and South America and on the ocean floors, and is sometimes used as a green earth pigment for paints. Monoclinic mineral of the amphibole (double-chain silicate) group. Glaucophane occurs as blue-gray sheets in dense metamorphic rocks such as schists, especially aat:300380383 glaucophane blueschist. aat:300298634 glazed terracotta Fired terracotta to which a vitreous glaze has been applied. Metamorphic rock, commonly rich in quartz and feldspar with a banded and foliated texture comprising bands of light colored minerals that alternate with bands of dark colored minerals. It is composed of mica, quartz, and schist, with additional iron, magnesium and silicates. It is formed at temperatures above 550 degrees Centigrade. aat:300011438 gneiss Gneiss is similar to granite in composition and may be classified as a type of granite, but it is produced by the alteration of igneous and sedimentary deposits, whereas granite is formed of igneous deposits. A yellow earth mineral that occurs naturally as an opaque crystalline material, primarily composed of iron hydroxide and varying in color from red to yellowish-brown. It aat:300379002 goethite (mineral) is used for pigment and large clumps have also been carved for small ornamental items. Pure metallic element having symbol Au and atomic number 79; a soft, inert, shiny reddish yellow metal that is very malleable and ductile. Gold has been highly valued and found in artifacts dating to before 5000 BCE. Native gold, found in quartz veins (vein gold) and alluvial deposits (placer gold), generally contains some silver and aat:300011021 gold (metal) copper. Gold is purified by dissolution in mercury or cyanide solutions, by melting, or by electrodeposition. The purity of commercial gold is expressed in karats which is the number of parts of gold in 24 parts of the alloy. Today gold is primarily used for monetary systems and for jewelry. aat:300010963 gold alloy Alloy in which gold is the principle element. Refers to sheets of gold that have been hammered or rolled very thin (typically around 0.1 micrometer, or 4 millionths of an inch, thick). In art, gold leaf has been aat:300264831 gold leaf applied to paintings, sculptures, manuscripts, and decorative arts since around 1500 BCE. In the 1920s, the process of creating gold leaf was successfully automated. Glass of a deep red color that is produced by a colloidal gold solution prepared by dissolving gold in aqua regia, sometimes including some tin or silver salts. Gold ruby aat:300190375 gold ruby glass glass was made by the ancient Egyptians and Romans; the ancient technique was lost until rediscovered in 17th-century Germany. Gold was also thought to be anti-toxic and to protect from poison anyone who drank from it. aat:300011075 golden beryl A variety of heliodor beryl that is golden in color. A coarse-grained igneous rock that has been subjected to metamorphic processes, formed by cooling of silica-rich magma below the surface of the earth at great depths and pressures. It is the most common intrusive acid igneous rock of the Earth's crust. Granite is commonly found on continents, but is virtually absent from the ocean aat:300011183 granite (rock) basins. The term "granite" refers to its visible granular composition. It has a visibly crystalline texture, is usually red, whitish, or gray in color depending upon its composition, is very hard and durable, and takes a fine polish. Granite is primarily composed of feldspar, quartz, and mica along with various other minerals in varying percentages. Granite is frequently used for buildings and monuments. aat:300010399 granite-powder cement Cement used in making floors of huts in Southern Africa. Granito del foro is an igneous rock which was once quarried at Mons Claudianus in Egypt. It is in fact a granodiorite rather than a granite, and is named for its use in aat:300380366 granito del foro buildings of the Roman Forum especially during the reigns of Trajan and Hadrian and in Tetrarchic imperial architecture. A type of granular acid igneous rock intermediate in composition between quartz diorite and quartz monzonite, containing quartz, oligoclase or andesine, and potassium aat:300011210 granodiorite feldspar, with biotite, hornblende, or, less frequently, pyroxene, as the mafic components. Granodiorite is the intrusive equivalent of rhyodacite. aat:300380522 grape seed oil Oil expressed from the seeds of Vitis vinifera grapes. aat:300011188 graphic granite A granite which, when polished, displays markings that give the effect of being inscribed with Hebrew or cuneiform writings. Naturally occurring crystalline form of carbon dimorphous with diamond. Graphite has a layered structure that consists of rings of six carbon atoms arranged in widely spaced horizontal sheets, and thus crystallizes in the hexagonal system, in contrast to the same element crystallizing in the octahedral or tetrahedral system as aat:300011098 graphite (mineral) diamond, resulting in very different characteristics in each. Graphite is opaque, soft, greasy to the touch, and iron black to steel gray in color; it occurs as crystals, flakes, scales, veins, bedded masses, or disseminations in metamorphic rocks. aat:300011689 gravel A coarse granular aggregate, larger than sand, formed either naturally or by crushing rock. Oily fat-based lubricant often derived from rendered animal parts, or a synthetic petroleum-derived product resembling this. Oily fat-based lubricant often derived from aat:300014268 grease rendered animal parts, or a synthetic petroleum-derived product resembling this. aat:300010493 great brick A term used to describe large thin bricks used in medieval England. Inexpensive glass, commonly of greenish or brownish color, which is caused by the presence of impurities, notably iron. It is often used to make bottles or windows. The aat:300210980 green glass (bottle glass) term is derived from its resemblance to forest glass, which is also called "green glass." aat:300010966 green gold (gold alloy) An alloy of gold, silver, and copper that is used to make jewelry; it is graded from 14 to 18 karats. aat:300011512 green marble Marble with a mineral composition resulting in a predominantly green color. aat:300011659 green slate Slate that has a component of chlorite, causing a greenish color. Any of various rocks that are green in color, including altered igneous rocks colored green by feldspar, hornblende, augite, nephrite, or other minerals, or low-grade aat:300386691 greenstone (rock) metamorphic rock containing actinolite, epidote, or albite. Greenstone has been used for carving and construction. A tough, gritty sandstone used for building, found in Yorkshire and other areas of England; it is the principal stone of the Southern Pennines, the heart of the gritstone aat:300011380 gritstone region. It is characterized by the angularity and large size of its quartz grains. There are many varieties of gritstone, some of which are quite strong. It was quarried by the Romans, was in use again before the Norman Conquest, and continues to be used in modern times. aat:300010615 grizzle Gray brick either made of special clay and used as facing or soft brick intended to be hidden or used in an unobtrusive location. aat:300264869 grog Refers to prevously burnt, finely ground pottery that is added to terracotta clay in order to open the pores. aat:300010847 ground glass Double-strength glass that has one side ground to a frosted finish, thus transforming the clear glass to an obscure glass. aat:300250545 groundwater Water in the upper surface of the earth which forms the water table that supplies springs and wells. aat:300013544 gulf red A bright, clear red iron oxide earth pigment that has since been replaced by light red. Carbohydrate containing exudates obtained from some trees or shrubs belonging to the family Fabaceae of the pea order Fabales. Gum is insoluble in alcohol and either soluble or swellable in water. Some plant gums are used in the form of water solutions in the manufacture of cosmetics, pharmaceuticals, and foods; when the water aat:300012866 gum (material) evaporates, a film having a considerable adhesive character is formed. Some gums, such as gum arabic, dissolve in water to give clear solutions. Other gums, such as gum tragacanth, form mucilages by the absorption of large amounts of water. May be distinguished from "resin" in that gum hardens in drying, but is usually soluble in water. Water-soluble gum that is exuded by two species, Senegalia senegal and Vachellia seyal, which were formerly classified under genus Acacia. Gum arabic is used in inks, aat:300012869 gum arabic paints, adhesives, pharmaceuticals, confections, and other products. Gummy exudate from various species of the genus Sterculia, notably from S. urens, a tree native to central and northern India. It occurs as tears of variable size and of a somewhat crystalline appearance, translucent, pale yellow, with a slightly acetic odor and a mucilaginous, slightly acetic taste. The gum is insoluble in alcohol, but aat:300012873 gum karaya swells in water to form a gel; it forms an extremely strong adhesive with small amounts of water. It is used as a dye thickener, textile coating, emulsifier, paper fiber binder, a base in marbling paper, medical adhesive, a denture adhesive, a thickener and emulsifier in foods, and as a laxative. It is also used to adulterate gum tragacanth due to their similar physical characteristics. Gum karaya has been available commercially only since 1920. aat:300012940 gum resin A vegetable secretion of shrubs and trees, consisting of a resin mixed with gum mucilage. Gum resin is generally insoluble in water, but dissolvable in alcohol. The balsam exudate obtained from several North American trees, including the longleaf pine, Pinus palustris, the Cuban pine, Pinus caribaea, and the loblolly pine, Pinus aat:300012875 gum thus taeda. Gum thus is a thick, yellowish, sticky mass with a characteristic piney odor. It is used as an additive in oil paints, an insecticide, a polish, and as an antiseptic agent. An exudate from several species of shrubs of the genus Astragalus, especially Astragalus gummifer, found in the dry regions of Iran, Iraq, Syria, and Turkey. The use of aat:300012876 gum tragacanth gum tragacanth dates from pre-Christian times. It used for textile sizing, printing, pastel crayon production, leather curing, furniture polishes, as an emulsifying, suspending, and thickening agent, pharmaceutically as a demulcent (coating) and as a binding agent in pill manufacture, and in processed foods. aat:300010767 gunite A construction material composed of cement, sand, or crushed slag and water forced through a pneumatic gun. The inspissated, milky juice of various trees of the Sapodilla family native to the Malaysian peninsula. It is a tough, pliable, moldable rubber-like material, although it lacks the elasticity of rubber and becomes brittle on exposure to air and sunlight. Gutta-percha vulcanizes with sulfur into a hard, waterproof material. From the late aat:300211567 gutta-percha 1840s, it was widely used for golf balls, imitation leather, joints in doll limbs, electrical insulation (especially underwater cables), and dental fillings. The name gutta- percha was sometimes used for any dark-colored molding material. It sets faster than "caoutchouc," which must be heated far longer. Naturally occurring soft white mineral that is commonly used as a retarding agent in portland cement, as a core in sheets of wallboard, as a white pigment, in grounds aat:300011099 gypsum for paintings, and is the main component of alabaster. aat:300010400 gypsum cement Cement containing gypsum, which is used as a retarder. aat:300207247 haematinum An Egyptian and Roman glass with a blood red color created by the dispersion of cuprous oxide crystals in black glass. Naturally occuring mineral composed of sodium chloride, usually colorless, cubic crystals. It is found as evaporite deposits in dry lakebeds, near the ocean, or as salt aat:300386504 halite domes underground. Halite deposits occur in Germany, Austria, Russia, France, India, Canada, and the United States. Generic name for any of a class of compounds formerly used as a fire-extinguishing agent. When exposed to flame, these chlorofluorocarbon gases release halogen atoms which interact with hydrogen atoms, suppressing combustion in the process. They also deplete the earth's ozone when exposed to solar ultraviolet light and have aat:300380067 halon consequently been withdrawn from use. Included in the group are Halon: dichlorodifluoromethane, CCl2F2; Halon 1211: bromochlorodifluoromethane, CBrClF2; and Halon 1301: trifluorobromomethane, CBrF3. Type of porcelain material comprising white china clay, or "kaolin," and "petuntse," which is a naturally fusible feldspathic rock. It is "hard fired" at the relatively high aat:300010663 hard paste porcelain (material) temperature of around 1450 degrees centigrade. It was developed first in China and produced in Europe after 1700. A principal class of soap that is created using faaty acids that are longer and tend to dissolve more slowly in water than soft soaps; for example, olive oil and caustic aat:300266180 hard soap soda lye would be used to create a hard soap. aat:300161511 hard solder High-melting brazing alloy, typically brass with silver, requiring temperatures ranging between 750 and 900 degrees Celsius to melt. aat:300011774 hard water Water that contains magnesium, calcium or iron salts. aat:300010866 heat-absorbing glass Glass that absorbs heat because it is opaque to infrared radiation; it nevertheless retains a reasonable degree of transparency to most other radiation. aat:300010780 heat-resistant concrete Any concrete that does not disintegrate upon exposure to constant or cyclic heating at a temperature below the level needed to form a ceramic bond. aat:300010867 heat-resisting glass Glass, usually borosilicate, with a low coefficient of expansion making it resistant to thermal shock. Glass that has been heat treated to induce surface compression in order to add strength. On breaking, it breaks into sharp pieces, but smaller than pieces of broken aat:300010871 heat-strengthened glass annealed glass. It does not dice, as does tempered glass on breaking. It is intermediate in strength between annealed glass and toughened glass. It is used in the curtain wall design as spandrel glazing of multistoried buildings. It is usually polished plate glass or paaterned glass on one surface of which is fused a colored enamel. aat:300343499 heelball Mixture of beeswax and lampblack used for making rubbings and polishing the shoes, particularly the edges of the soles. A white ore composed of hydrous zinc silicate. It is a minor ore of zinc that occurs in zinc mines worldwide with significant deposits in Siberia, Romania, Sardinia, aat:300390895 hemimorphite Slovenia, Belgium, Germany, Poland, England, Mexico, and the United States. Formerly confused with smithsonite, and both were called calamine; see "calamine (mineral admixture)." aat:300014291 hempseed oil Oil obtained from the seeds of the hemp plant. Used as a substitute for linseed oil. aat:300386614 hexosamine The amino sugar derivative of the monosaccharide hexose in which the hydroxyl group is replaced with an amine group. aat:300014823 hide glue Animal glue made from degraded collagen obtained from skin and hide. Concrete that conforms to a set of standards for high workability, high strength, and high durability established by the Strategic Highway Research Program (SHRP), an aat:300387519 high performance concrete infrastructure research initiative authorized by the U.S. Congress. aat:300010916 high-carbon steel Steel having a carbon content in excess of 0.5%. A kind of portland cement that is often used when the temperature is below freezing because it completely hardens in a shorter amount of time than other kinds of aat:300010378 high-early-strength cement portland cement. Steel, containing carbon, manganese, and small amounts of other elements, characterized by high strength and corrosion resistance. Exposure to air creates a pebbly, aat:300010923 high-strength low-alloy steel rusty-looking surface that works to reduce corrosion; this surface film turns a deep purple-brown after a number of years which is why high-strength low-alloy steel is sometimes used for exposed structural members of buildings. aat:300010704 hip tile A saddle-shaped tile used to cover the external angles of a roof where two sloping sides meet. A hollow clay masonry unit whose net cross-sectional area in every plane parallel to the bearing surface is not less than 60% of its gross cross-sectional area measured aat:300010523 hollow brick in the same plane. In British usage it refers to a brick with holes in it that total at least 25% of its volume, the holes being not less than 3/4 in. (1.91 cm) wide or 3/4 sq. in. (4.84 sq. cm) in area. Generally, water dedicated to sacred uses and used for ritual purification of persons and things. More specifically, water blessed by a priest and used in various rites and aat:300264702 holy water devotional acts, such as baptisms and blessings. Any of numerous organic compounds that serve as chemical messengers. They are secreted by a gland or organ into the body fluids of an animal, particularly the bloodstream, by a gland or organ, are transported to another part of the organism, and trigger or regulate particular functions such as growth, metabolism, aat:300265405 hormone reproduction, and the functioning of various organs. The term may also refer to similar compounds produced by plants or produced synthetically. The term was coined in 1905 from the Greek "horman," meaning "to set in motion." aat:300380298 hornblende A dark green to black member of the amphibole mineral group, hornblende is common constituent of metamorphic and igneous rocks such as granite, basalt, and schist. aat:300386616 hornblendite An igneous rock consisting mainly of the amphibole mineral hornblende. Fine-grain silicate rock produced by contact metamorphism, where the rock has been baked and indurated by the heat of intrusive granitic masses and have been aat:300011442 hornfels rendered massive, hard, splintery, and in some cases exceedingly tough and durable. Dark brown or black non-living organic substance derived from microbial decomposition of plant and animal substances on the surface of the earth. Living plants derive aat:300014333 humus nutrients from the forms created by this decomposition. aat:300255935 huntite White mineral consisting of calcium magnesium carbonate occurring as chalklike masses and used as a white pigment. aat:300011166 hyacinth (zircon) A transparent red or brown variety of zircon, sometimes used as a gem. aat:300211728 hyalith glass A dense opaque glass of a red or black color made at the glassworks of Count von Buquoy in southern Bohemia in the 19th century. aat:300011342 hydraulic limestone Limestone containing silica and alumina and yielding a lime that will harden under water. A member of a large group of organic chemicals, containing only the elements hydrogen and carbon. They are major constituents of crude petroleum and natural gas, aat:300264224 hydrocarbon from which certain fractions are extracted for use as fuel and as raw materials for the chemical industry. Nonmetallic chemical element (H). It is a colorless, odorless, tasteless gas, the lightest chemical element, and is used in rocket fuels and balloons. Its most important aat:300379581 hydrogen compound (with oxygen) is water. A colorless corrosive gas, the hydride of fluorine and an extremely powerful halogen acid, hydrogen fluoride is used as a catalyst and a fluorinating agent. Its chief use is aat:300380525 hydrogen fluoride in making fluorine-containing refrigerants such as freons. In a conservation context, hydrogen fluoride is considered as an atmospheric pollutant which damages metal structures, and buildings or monuments made of limestone. Toxic, flammable, colorless gas that smells like rotten eggs. Hydrogen sulfide may be created by decay of organic maater or obtained as a byproduct of refining aat:300380183 hydrogen sulfide carbonaceous fuels such as natural gas, crude oil, and coal. As an atmospheric pollutant, hydrogen sulfide blackens lead pigments, and tarnishes silver. aat:300386617 hydromagnesite A marble-like mixed-mineral stone. Its name alludes to its composition: a hydrated magnesium composite. A complex calcium phosphate, a naturally occuring mineral form of calcium apatite, that serves as an important component of tooth enamel and vertebrate bone. In an aat:300379782 hydroxyapatite archaeological context, hydroxyapatite from human and animal remains is studied to reconstruct ancient diet. A neutral cellulose derivative, hydroxyethyl cellulose (HEC) is a granular, water-soluble thermoplastic polymer used as an emulsifier, thickener and film former in many aat:300386840 hydroxyethyl cellulose types of solutions. It is also used as a sizing material. Hydroxypropyl cellulose (HPC) is a water-soluble cellulose ether used as an emulsifier, thickener, and suspending agent in many types of solutions. In conservation, HPC aat:300379929 hydroxypropyl cellulose is used as a consolidant for leather afflicted by "red rot", and as a fixative for pigments and dyes. aat:300011781 ice The solid form of water, produced by freezing. Any of various crystalline or glassy rocks formed by the cooling and solidification of magma or other molten earth material. Igneous rocks comprise one of the three aat:300011178 igneous rock principal classes of rocks, the others being metamorphic and sedimentary. aat:300219700 ilmenite Titanium ore found in igneous rock and supplies a major portion of the world's titanium; source for titanium white pigment and used in ceramic glazes. aat:300010682 imbrex Tiles, semicircular in shape, which fit over the joints in a tile roof. aat:300262484 impactite Glassy or crystalline material formed in or around meteor craters by the fusion of Earth rock and meteorite fragments upon impact. Maori pounamu stone that is paler than other varieties, often of a pearly-white or gray-green nephrite, ranging from translucent to opaque. It can change color over aat:300379292 inanga (stone) time, developing a light-olive tint as it ages and oxidizes. An inductively coupled plasma (ICP) is a type of high-temperature plasma (ionized gas) source generated by electric currents produced by electromagnetic induction. It aat:300379537 inductively coupled plasma is used to determine elemental content of materials in ICP spectrometry. aat:300011171 industrial jewel Hard stone, usually ruby and sapphire, used chiefly for bearings and impulse pins in instruments and for recording needles. Mass of any type of metal, cast into convenient shape for storage and transportation, to be rolled, forged, melted, or otherwise processed later. In some periods and aat:300137865 ingot cultures, such as in China, ancient Italy, and parts of Africa, they have been used as currency and as ceremonial objects. aat:300010360 inorganic material Material that contains neither hydrocarbons nor any of their derivatives. aat:300391387 inorganic sulfide Ionic compounds or salts that contain a negatively charged sulfide ion. aat:300014587 insect wax Any of various waxes that are produced by insects, such as beeswax, lac wax, creosote lac wax, and Chinese insect wax. aat:300010756 insulating concrete Concrete having low thermal conductivity and used as thermal insulation. aat:300010872 insulating glass Window glass made of two sheets of glass separated by metal bonded to the edges of the glass, leaving an insulating layer of dehydrated air between the two panes. aat:300011212 intermediate igneous rock Igneous rocks classified according to chemical or mineralogical parameters, containing between 52 and 63% SiO2; examples are andesite and dacite. Igneous rock formed at great depth by crystallization of magma and/or by chemical alteration, as contrasted with volcanic rock. Typically of granitoid texture and aat:300011244 intrusive rock medium- or coarse-grained. A nonmetallic element of the halogen family with atomic number 53 and symbol I. It is a dark crystalline solid used as an additive to salt to prevent iodine insufficiency aat:300380217 iodine and is used in dyes, photographic film, x-ray contrast media, and other applications. aat:300380464 ion-exchange resin Any of the range of synthetically polymerized organic compounds suitable for use in ion exchange. aat:300014461 ionomer polymer Polymer composed of macromolecules in which a small but significant proportion of the constitutional units has ionic or inonizable groups, or both. Pure metallic element having symbol Ir and atomic number 77; a hard, brittle silvery-white metal of the platinum family. Iridium is the most corrosion-resistant metal aat:300380172 iridium and the second densest chemical element. Pure metallic element having symbol Fe and atomic number 26; metallic iron is silvery in color, lustrous, soft, ductile, malleable, and slightly magnetic; it rusts when aat:300011002 iron (metal) exposed to moist air. It is rarely found as a native metal (telluric iron) except in meteorites (meteoric iron). Iron is most often found throughout the world as iron oxides (hematite, magnetite, limonite, and siderite) mixed with other ores. aat:300010904 iron alloy Alloy in which iron is the principle element. aat:300311188 iron glance Specular iron ore, that is ore having a luster that indicates its metallic nature. aat:300379991 iron ore Refers to any rock or mineral from which iron can be extracted. Refers to a variety of dense, permanent pigments that produce a wide variety of red shades ranging from light, bright red to a deep purplish red. Pigments can be natural, earth pigments (hematite, Indian red, Venetian red) or synthetically prepared pigments (light red). All iron oxide reds are stable, permanent pigments with good aat:300013537 iron oxide red (pigment) tinting strength and are the primary colorant in ochers and siennas. The pigment was first manufactured in the early 18th century. Today it is often a furnace product made from steel-mill waste. aat:300014822 isinglass (fish glue) A gelatin made from the dried swim bladders, or fish sounds, of sturgeon and other fishes. aat:300380528 isobutyl methacrylate Colorless liquid polymer used as a water-repellent synthetic resin varnish and barrier coating. It is resistant to discoloring, aging, temperature changes, and exposure. aat:300011857 ivory (material) The modified form of dentine found on the tusks of mature elephants, and for similar material from any tusked or large-toothed mammal such as a walrus or narwhal. General term for several varieties of hard and soft, fine-grained rock composed of jadeite, nephrite, serpentine, or other mineralogically related materials; usually having a color ranging from dark green to green-white. Jade takes a high polish and has been used since prehistoric times for jewelry, small utensils, carvings, vases, and other aat:300011119 jade (rock) ornamental objects. Some processing techniques have been used to enhance the color of inferior stones: B-jade has been bleached to remove brown stains, while C-jade has been impregnated with resins to increase its translucency; A-jade is untreated. Mineral consisting of sodium aluminum silicate, usually containing small amounts of iron, calcium, and magnesium. It constitutes the more valuable variety of jade, aat:300011121 jadeite ranging in color from pale to dark green that is commonly called jade; neprhite is the other mineral called "jade." Jadeite is highly valued for its translucent glassy appearance; it is found chiefly in China, Myanmar (formerly Burma), and Mexico. aat:300386620 jarosite (mineral) An amber or brownish yellow-colored hydrous sulfate of iron and potassium found as rhombohedral crystals is sulfurous layers of iron ore. aat:300011151 jasper Any red chert or chalcedony. aat:300045514 jet (coal) A dense, black, semiprecious form of lignite that takes a brilliant polish and is used ornamentally, particularly in Victorian mourning jewelry. aat:300255931 jojoba oil Oil extracted from the seed of jojoba, used widely in the production of cosmetics and lubricants. aat:300010496 jumbo brick Brick fired at the nominal dimensions of 4 by 4 by 8 inches. aat:300012943 juniper resin Resin from true juniper trees, of the genus Juniperus. For the resin of the genera Callitris and Tetraclinis, which is sometimes called "gum juniper," use "sandarac." aat:300379298 kahurangi (stone) Kahurangi is the rarest variety of Maori pounamu stone. Usually a variety of nephrite, it is highly translucent and often comes in vivid shades of green. Hydrated aluminum silicate clay. It is used for making porcelain for china and chemical porcelain for valves, tubes, and fittings, as a pigment and filler in paint and aat:300010445 kaolin plastic, an abrasive powder, and in paper to yield a glossy surface. A common clay mineral of the kaolin group; hydrated aluminum silicate mineral which is the principal constituent of kaolin clay. Kaolinite crystals have a lamellar (plate- aat:300209724 kaolinite (mineral) like) structure that gives the clay its slippery feel. It is a natural alteration product of aluminum silicate rocks, such as feldspar. Pure kaolinite is a primary clay; most secondary clays contain only a small percentage of kaolinite, although an exception is ball clay found in Wareham, England. aat:300014315 kapok oil A semidrying oil obtained from the seeds of the kapok tree. A medium-hard variety of copal resin obtained from the kauri pine, Agathis australis, native to New Zealand. It is a pale yellow to reddish brown resin with a piney odor. Kauri can be collected as a resin or found in fossilized deposits; today it is scarce. It was widely used in the early 20th century for floor and furniture varnishes, in aat:300012917 kauri (resin) adhesives, enamels, and linoleum. A medium-hard variety of copal resin obtained from the kauri pine, Agathis australis, native to New Zealand. It is a pale yellow to reddish brown resin with a piney odor. Kauri can be collected as a resin or found in fossilized deposits; today it is scarce. It was widely used in the early 20th century for floor and furniture varnishes, in adhesives, enamels, and linoleum. The most common variety of Maori pounamu stone that comes in many shades, from strong rich green to dark green; often a translucent nephrite. It is often aat:300379307 kawakawa (stone) characterized by small dark inclusions, which is considered an addition to its character. A natural fibrous protein that is the primary building block for epidermal tissue. Keratin contains all of the common amino acids, but has higher amounts of cystine than aat:300193683 keratin other fibrous structural proteins. Soft keratins are found in the external layers of skin, wool, hair, feathers, while hard keratins are the major components of tortoise shells, nails, hoofs, scales, bills, and claws. In addition to usage in their natural form, since the mid-1600s keratin has been molded into buttons, combs, and buckles. aat:300014321 kernel oil Generally, an oil that is extracted from the kernel or pit of a fruit. aat:300380063 khondalite A granitoid rock found in southern India used as a material in local construction and sculpture. Named (by T.L. Walker in 1902) after regional tribe, the Konds. aat:300010473 king closer A rectangular brick, one end of which has been cut off diagonally to half the width of the brick; used as a closer in masonry. Decorative technique in which thin pieces of gold and silver leaf that have been shaped into squares, strips or lozenges are applied to lacquerware, paintings, and aat:300310649 kirikane sculptures. Originally introduced to Japan during the Nara period (710-794), the technique was popular from the Heian period (794-1185) through the Kamakura period (1185-1333). A resinous substance excreted by the lac insect, especially those who live on the twigs and soft new branches of several varieties of soapberry and acacia trees. Lac is aat:300012946 lac (resin) used in the manufacture of varnishes (shellac), sealing wax (lac wax), and red colorants (lac dye) as early as ca. 1200 BCE in India. The word "lac" is the English version of Persian and Hindi words meaning "hundred thousand," indicating the large number of the tiny insects required to produce lac. aat:300233429 lacy glass Collectors' term used to describe pressed glass with a stippled background and usually a scroll-and-flower design; made from the mid-1820s to the mid-1840s. aat:300012980 lake asphalt Natural asphalt that is collected in pits or lakes, often a rather elastic variety of asphalt. Thin sheet of superimposed layers of plastic bonded or impregnated with resin and compressed under heat. Distinguished from "plastic laminate" which is used for resin- aat:300256237 laminated plastic impregnated materials, such as paper or fabric, produced under heat and high pressure. A semisolid, waxy material extracted from sebaceous glands of wool-bearing animals, particularly sheep, genus Ovis. It is a complex mixture of 33 high molecular weight alcohols and 36 faaty acids, including cholesterol. One of the unique properties of lanolin is that it can incorporate up to 25-30% water without separation. Since it is aat:300014595 lanolin readily absorbed by skin, lanolin is used as an emollient in cosmetics, ointments, leather, and as a rust preventative. Lanolin's role in nature is to protect wool and skin of the animal against the environment, also having a role in hygiene. aat:300011122 lapis lazuli (rock) A granular crystalline rock composed essentially of lazurite and calcite. This is an old name for gem-variety lazurite. A residual product of rock decay that is red in color and has a high content in the oxides of iron and hydroxide of aluminum and a low proportion of silica. Used in African aat:300014334 laterite and Asian building construction. Viscous, milk-like fluid composed of resin or wax in the form of tiny globules in aqueous suspension, obtained especially from rubber trees; used for many rubber aat:300013021 latex (organic material) applications, such as adhesive. Use also for a water dispersion of synthetic rubber and of rubberlike plastic. Copper-zinc-tin alloy, sometimes also including lead, made by melting ground calamine ore with charcoal and copper; used in the Medieval period for weights and aat:300198675 laaten utensils. A strongly alkaline cleaner having the primary ingredients sodium carbonate and sodium bicarbonate, used in textile processing and commercial laundry soaps. Such an aat:300375657 laundry soda alkaline soap causes cottons to yellow. Rare halide mineral, oxy-chloride of lead, occuring as colorless, transparent striated crystals. Laurionite forms when salt water comes in contact with lead bearing slag, aat:300380388 laurionite or as an oxidation product in lead ore deposits. The presence of laurionite in some ancient Egyptian cosmetics suggests that the mineral was purposely synthesized by the Egyptians using "wet" chemistry. aat:300011249 lava Molten volcanic rock that issues from a volcano or fissure in the earth's surface; also, the same material after being cooled and solidified. aat:300014262 lavender oil A colorless to yellowish aromatic essential oil obtained from the flowers of several species of lavender; used as a retardant in oil paint. aat:300209742 lazurite An intense blue or violet-blue feldspathic mineral of the sodalite group; it is the principle constituent of lapis lazuli. Pure metallic element having symbol Pb and atomic number 82; soft, dense ductile metal of a dull gray color, shiny when freshly cut, occuring naturally most often as a sulfide in the mineral galena. Other lead minerals include anglesite (lead sulfate) and cerussite (lead carbonate). Native metallic lead was found and used from about aat:300011022 lead (metal) 3600-2600 BCE when the technique for obtaining lead from roasting the sulfide ore (galena) was discovered. Lead was used to make small cast items such as coins and statuettes, plumbing pipes, spires, statues, cisterns, gargoyles, pigments (lead white, litharge, orange mineral, etc.), as a component in pottery glazes, for roofing, flashing, stained glass windows, as a soft solder, and as radiation shielding. aat:300010932 lead alloy Alloy in which lead is the principle element. aat:300010959 lead bronze A bronze alloy with a high lead content, the 80:10:10 mixture, making it a soft matrix metal ideal for use in bearings. aat:300241088 lead compounds Compounds consisting of the chemical element lead. Glass containing a high proportion of lead oxide and having a relatively high refractive index, with poor acid resistance and low rigidity; used in many optical aat:300010811 lead glass components, neon-sign tubing, and light bulbs. Insoluble black compound that occurs naturally as galena, the chief ore mineral of lead. It can also be synthesized by reacting a soluble lead salt with hydrogen sulfide or aat:300380269 lead sulfide sodium sulfide. When crushed, lead sulfide becomes a powder which is used in photoconductive cells, and as a pigment in ceramic glaze. Yellow pigments composed of lead stannate that were used in European painting from the beginning of the 14th century until the early years of the 18th century, when it was largely replaced by Naples yellow (lead antimonate yellow). Two distinct varieties are known, both made by heating together lead and tin oxides in a furnace, with aat:300311443 lead tin yellow (lead compound) one type having sand (silicon dioxide) introduced. Both pigments are stable, used as opacifiers, colorants in glass and ceramic glazes, and in all paint media. Lead-tin yellow was often used in mixtures with other pigments such as lead white, vermilion, azurite, verdigris, and indigo. aat:300011039 leaf (metal) Metal beaten or rolled out to extreme thinness for use in gilding or other decorative processes. A viscous oily liquid that is found in certain animal and vegetable maater. Lecithins are composed of a mixture of diglycerides of faaty acids (stearic, palmitic, oleic, aat:300013024 lecithin linolenic and linoleic) linked to the choline ester of phosphoric acid. Commercially, lecithin is obtained from soybean, corn, and egg yolk. It is used for emulsifying, dispersing, and wetting, added to food products, paints, printing inks, plastic molding as a release agent, textiles as a lubricant, and leather as a dressing. A yellow colored essential oil expressed from the rind of the lemon fruit. Lemon oil is used in flavoring, soaps, perfumes, cleaning, furniture polishes, and to secure gold aat:300183857 lemon oil leaf temporarily to the covering material of a book before blocking or tooling. Essential oil distilled from species of Cymbopogon grass, and used as a stabilizer in soaps, perfumes, and cosmetics. It contains 70–80 percent citral, which may be aat:300266811 lemongrass oil isolated by distillation or from the oils of verbena and citronella. aat:300011477 lepanto marble A shell marble quarried near Plaatsburg, New York. aat:300136931 lepidolite A mineral of the mica group; it commonly occurs in rose- or lilac-colored masses made up of small scales, as in pegmatite. A type of deeply etched, crystalline glass developed by Bernard O. Gruenke and his son, Bernard E. Gruenke, Jr., in the 1970s. The glass was inspired by a aat:300265065 leptat glass Czechoslovakian etched glass exhibit they saw at the World's Fair in Osaka, Japan; they called their glass "leptat," a word derived from the Czech meaning "to etch," in honor of its inspiration. The etching technique was later patented. aat:300011586 lesbio A yellowish white marble with ashy black stains and large conspicuous crystals; it originates from the island of Lesbos in Greece. A permanent, opaque, synthetic pigment having a pale red or reddish orange color. It is composed of red iron oxide, obtained by either roasting yellow ocher or as a by- aat:300380443 light red (pigment) product from steel-mill waste. It is used in artists' paints, marine paints, metal primers, and as a filler in rubbers and plastics. aat:300183825 lignin Impure colorless to brown crystalline maater found in wood; from the secondary wall structural support in wood cells. aat:300211957 lignite A soft coal, usually dark brown, often having a distinct woodlike texture, and intermediate in density and carbon content between peat and bituminous coal. A compound constituting the essential part of woody cell walls of plants in which cellulose fibril aggregates are embedded in a matrix material consisting of aat:300380349 lignocellulose hemicelluloses and lignin. Lignocellulosic biomass is used as fuel and is the feedstock for the paper and pulp industry. aat:300010748 lime concrete A concrete made from a mixture of lime, sand, and gravel, widely used before the lime matrix was replaced by portland cement. A name given to a type of glass developed in 1864 by William Leighton as a substitute for lead glass in making inexpensive bottles. Calcined limestone, or lime, is used aat:300210974 lime glass to produce a glass whose advantages are that it is inexpensive, lightweight, cools quickly, and is less resonant. Pale green, volatile oil obtained from the rinds of the lime fruit. Lime oil is normally prepared by steam distillation; its components are limonene and citral. It is used in aat:300375407 lime oil flavoring, perfumes, insecticide, antiseptic, cleaning products, aromatherapy, and as a source of vitamin C. aat:300011286 limestone General name for a sedimentary rock existing in many varieties, consisting primarily of calcite or dolomite. Limonite refers to any hydrated iron ore. A brownish yellow deposit, it is formed by precipitation in marshy areas and is found mixed in clay and sand as loose powder or aat:300379931 limonite as a mass. Limonite is also called bog iron ore. aat:300014292 linseed oil Popular drying oil used as a paint medium; hardens over several weeks as components of the oil polymerize to form an insoluble matrix. Any enzyme which splits triglyceride fats into their component faaty acids and glycerol. Lipase, found in the body, aids in the digestion of food. Lipase, added to aat:300380040 lipase detergents, aids cleaning. In conservation, lipase is sometimes used for removal of oil-based varnishes from paintings and of oil stains from drawings. Any of the large group of fats, oils, waxes, sterols, and triglycerides that occur in living organisms and are characteristically soluble in certain organic solvents but only partially soluble in water; they are oily to the touch. With carbohydrates and proteins, lipids are one of three types of materials that compose living cells. The structure of lipids range from simple straight chain hydrocarbon to complex ring structures. They can be subdivided as 1) faaty acids, 2) neutral fats, 3) phospholipids, 4) aat:300013022 lipid glycolipids, 5) aliphatic alcohols and waxes, 6) terpenes, and 7) steroids. Any of the large group of fats, oils, waxes, sterols, and triglycerides that occur in living organisms and are characteristically soluble in certain organic solvents but only partially soluble in water; they are oily to the touch. With carbohydrates and proteins, lipids are one of three types of materials that compose living cells. The structure of lipids range from simple straight chain hydrocarbon to complex ring structures. They can be subdivided as 1) faaty acids, 2) neutral fats, 3) phospholipids, 4) glycolipids, 5) aliphatic alcohols and waxes, 6) terpenes, and 7) steroids. aat:300013006 liquefied petroleum gas Compressed gas that consists of flammable hydrocarbons such as propane and butane, and is used especially as fuel or as raw material for chemical synthesis. Carbon dioxide used in its liquid state as a non-toxic, environmentally friendly solvent for cleaning, degreasing, and decontaminating materials. Liquid carbon dioxide is aat:300386435 liquid carbon dioxide also used to promote plant growth in a greenhouse environment, and, stored under pressure in a tank, as a carbon dioxide fire extinguisher. And has been used in the treatment of ethnological and natural history museum collections. A crystalline form of lead monoxide, the oxidized product of molten lead that has been stirred or atomized to incorporate air then cooled and ground to form the yellow aat:300013921 litharge powder. It is used as a drier in paint and varnish, for the fluxing of earthenware, and in the manufacture of glass. Litharge tends to be slightly more orange than massicot, another crystalline form of lead monoxide, due to the presence of small amounts of red lead oxide. Pure metallic element having symbol Li and atomic number 3; a soft, silver-white metal, the lightest element in the alkali metal series. It is obtained from minerals, such aat:300380205 lithium as spodumene, in which it occurs or as a byproduct of potash and borax. Use also for this metal as processed and formed for use as a heat transfer medium in nuclear reactors or as a strengthener in alloys and many manufactured products such as ceramics and glass. Its salt is used in psychiatric medications. Salt formed by adding hydrochloric acid to lithium. Lithium chloride is the compound used to produce lithium metal by electrolysis. Thanks to its hygroscopic capacity, it aat:300380529 lithium chloride is used for controlling relative humidity within a sealed environment. It is also used as a soldering flux, and to produce red colors in pyrotechnics. Refers to rock in its original environment, as opposed to having been quarried. It typically refers to rock that is carved or otherwise used in situ, often to sculpture or aat:300264873 living rock architecture carved in situ. aat:300379312 lizardite A type of fine-grained, platy serpentine that is mottlish yellow with dark gray or black patches. The name refers to its resemblance to a snake's skin. aat:300014335 loam Soft, easily worked soil containing sand, silt, and clay. Gum produced from grinding the seeds of the carob tree to a fine powder, which dissolves in hot water and cools to form a stable gel that is an excellent film former. The aat:300375539 locust bean gum gum is used as dye thickener, and as size for food, cosmetics, textiles, and paper. Locust bean gums have been detected in the wrappings of Egyptian mummies. aat:300379789 lodestone Magnetite that possesses polarity. Lodestones, or natural magnets, have been found in Siberia, the Island of Elba, and in Arkansas. aat:300010911 low-carbon steel Steel having a carbon content under 0.2%. aat:300163250 low-heat cement A type of portland cement whose chemical composition has been altered so that little heat is produced during hardening. Petroleum products, usually heavy distillates after kerosene, that are classified based on their viscosity for various purposes, ranging from very thin oils for high speed aat:300014271 lubricating oil textile machinery, to heavier, tackier, or stickier oils for bearings or open gears. Automobile oil is the most common in the United States. aat:300011490 lucullite Egyptian marble colored black by carbon. A group of shell marbles, the name deriving from 'lumaca,' the Italian word for snail. There are both ancient and modern varieties; the best known modern lumachella aat:300011478 lumachella comes from Tirol in Austria and is dark gray-brown with shells retaining their pearly lining. aat:300011206 luxullianite A coarse red and black stone composed of red orthoclase, gray quartz, and black tourmaline. aat:300011469 madrepore marble A marble containing fossil madreporian corals. aat:300386621 maghemite Strongly magnetic iron oxide mineral closely related to hematite and sometimes found as a corrosion product on archaeological objects made of iron. aat:300010410 magnesia cement Magnesium oxide mixed with water, often with the addition of asbestos fiber; used to cover such things as steam pipes and furnaces. aat:300011346 magnesian limestone Limestone containing the combined carbonate of lime and magnesium, and frequently used for building. aat:300133242 magnesite White to bluish gray mineral,. It is used in the manufacture of brick and as an ore of magnesium. Pure metallic element having the symbol Mg and atomic number 12; the lightest metal that is stable under ordinary conditions, silvery white in color. Use also for this aat:300011024 magnesium metal as processed and formed, usually in combination with other substances, to make various objects and materials. White crystalline salt that occurs in nature as the mineral magnesite and may be prepared artificially by precipitation. It is used in pigments, inks, glass, ceramic glazes, aat:300379925 magnesium carbonate (mineral) and dentifrice. Magnesium carbonate has also been used as a sorbent powder for water-free (dry) cleaning of jewelry, doll hair, and other items. Aqueous solutions of magnesium carbonate are used for neutralization and alkalization of paper. Any of the salts of magnesium and phosphate, which may appear in monobasic, dibasic, or tribasic form. Deposits of magnesium phosphates bobierrite, newberyte and aat:300379781 magnesium phosphate struvite are found in ivory artifacts and excavated mammoth and elephant tusks. aat:300380253 magnesium phytate Refers to the magnesium salt of phytic acid. In conservation, used in a solution to inhibit iron gall corrosion on manuscripts. Any of several silicates containing magnesium; they are generally inert minerals used as fireproofing materials, abrasives, or fillers in paint and paper. The most common aat:300380531 magnesium silicate hydrated forms of magnesium silicate found in nature are asbestos and talc. aat:300386622 magnesium sulfate A white salt used medicinally as a laxative and anticonvulsant. In conservation science it is encountered as a salt weathering deposit on stone. Black opaque mineral composed of ferro-ferric oxide that is strongly magnetic; a common mineral in large deposits in Sweden, Norway, the Urals, Italy, Switzerland, aat:300011110 magnetite Australia, Brazil, United States, and Canada. Magnetite is brittle and fractures unevenly. When it possess a polarity, magnetite is called lodestone. Magnetite was used in antiquity for jewelry, amulet beads, seals and as a substitute for black pearls. It is also used as a black pigment in paints, linoleum, ceramic glazes, and glass. aat:300213343 mail (metal fabric) Metal fabric consisting of iron or steel rings, riveted or pressed together, typically used in armor. A green mineral composed of basic copper carbonate occurring naturally with the blue copper carbonate mineral called azurite, with malachite being the more abundant aat:300011123 malachite (mineral) of the two.The compact green variety has alternate irregular bands of light and dark green, and is used mainly for table tops, vases, veneer, and some jewelry. Both malachite and azurite have been used as gemstones and paint pigments since before 3000 BCE. aat:300010449 malm A light clayey soil containing chalk or an artificial mixture of clay and chalk used in the manufacture of bricks. Ancient ivory originating from the tusks of extinct mammoths, usually from individuals that are 10,000 years old or older, but preserved in frozen environments. aat:300390930 mammoth ivory Mammoth ivory was formerly abundant in Siberia; it was exported to China and Europe from medieval times. Pure metallic element having symbol Mn and atomic number 25; hard, brittle, silvery metal. Use also for this metal as processed and formed, usually in combination with aat:300011025 manganese other substances, to make various objects and materials. aat:300136729 manganese bronze Brass containing iron and manganese which, because of its hardness and crystalline structure, is named as a bronze. Manganite is an oxide ore mineral of manganese that forms dark steel gray to iron black crystal bundles or fibrous masses. A pigment derived from manganite was used aat:300380533 manganite in prehistoric cave paintings. A metamorphic, hard, dense, crystalline stone primarily composed of calcium carbonate; it is limestone or dolomite that has been metamorphosed with heat and pressure. Pure calcite marble is white, but impurities produce a wide variety of coloring and paaterns. It is finely grained and polishes to a smooth, high gloss. It is used aat:300011443 marble (rock) primarily for statuary and buildings. Marble has been quarried from sites around the world since at least the 7th century BCE. The term can also refer more broadly to any crystallized carbonate rock, including true marble and certain types of limestone, that will take a polish and can be used for architectural and ornamental purposes. aat:300133202 marble dust Finely ground chips used as a filler or abrasive in hand soaps and for casting. aat:300207336 marbled glass Glass decorated with haphazard streaking of two or more colors to resemble marble. A mineral with the same composition as pyrite (fool's gold) but differing in crystal structure. It can be faceted like a gemstone; it was popular in the 1920s to 1930s, aat:300011111 marcasite usually set in sterling silver. It is commonly found as nodules and concretions in sedimentary rocks. aat:300011256 marekanite Semitransparent, smoky-colored obsidian nodules of Arizona ore; used in Indian silver jewelry. Composite material made from scrap leather pieces mixed with white adhesive, which is then pressed and dried and the surface shaved or planed; developed in the mid- aat:300262402 maril 20th century by English bookbinder Philip Smith. aat:300010451 marl Calcareous clay containing up to 40% calcium carbonate. aat:300011279 marlstone Shale that is calcareous or dolomitic and is used with limestone in making portland cement. aat:300011631 marmolite A thin, laminated serpentine marble, usually pale green. A hard, crystalline solid solution of carbon in iron, martensite is the chief constituent of hardened steel. It is a decomposition product of austenite formed by rapid aat:300380042 martensite quenching from high temperatures. aat:300010922 martensitic stainless steel Stainless steel having a relatively high proportion of chromium, ranging between 12 and 17%, and a relatively high proportion of carbon. A type of portland cement that is generally more workable than normal portland cement. They usually contain a portland cement base with hydrated lime, crushed aat:300010383 masonry cement limestone, diatomaceous earth or granulated slag to aid in spreading. Heavy yellow powder composed of lead monoxide, both the native mineral as well as lead monoxide produced by heating lead carbonate to 300 C. It is used as a drier in aat:300266236 massicot oil, as a low-fire flux in making ceramics and glass, as a yellow pigment in paints and glazes, in thin layers to produce iridescent colors on brass and bronze, as a filler for rubber, and to produce artificial tortoiseshell and horn. Gum exudation of small evergreens native to the Mediterranean countries, soluble in both alcohol and turpentine; used for artists' paint and coating lacquer. Mastic aat:300014837 mastic (resin) varnish becomes yellow and brittle with age. Mastic was used in 16th and 17th century recipes for oil-resin varnishes; in the 19th century, mastic was a popular clear, glossy spirit varnish for oil paintings and was also used as an additive in oil medium. By the 20th century, its use was superseded by dammar. Tile with one face molded to look like the face or end of a brick; it was particularly popular between 1784 (the year the brick tax was passed in England) and 1850 (when aat:300010686 mathematical tile the tax was repealed). It would be nailed to baatens on a timber frame or other wall, or, occasionally, bedded into plaster rendering over cobble stones or pebbles. aat:300010915 medium-carbon steel Steel having a carbon content ranging from 0.2 to 0.5%. aat:300375655 medium-curing asphalt Cutback asphalt that has the adition of kerosene, which is less volatile than other additives, causing a slower evaporation process. aat:300076527 meerschaum Massive form of sepiolite used especially for tobacco pipes. aat:300123562 megaliths Refers to massively large stones, especially those very roughly worked or left as found; used in various ancient monuments. aat:300014525 melamine A white, crystalline, slightly water-soluble solid used chiefly in organic synthesis and in the manufacture of resin, especially melamine resin. Molding powder first introduced by Bakelite Ltd. in the early 1960s. Characteristics of this material include a range of intense bright colors. They have a good molding aat:300014545 melamine phenolic latitude and dry heat dimensional stability. Applications include handles for appliances where heat-resistant colored material is called for. Melanterite is hydrated iron sulfate formed after decomposition of pyrite or other iron materials by action of surface waters in mines. It occurs as dull, translucent green aat:300386623 melanterite crystals on mine walls. Formerly used to make an inky pigment, melanteria. Pure metallic element having symbol Hg and atomic number 80; a lustrous silvery metal that is liquid at ordinary temperatures. Use also for this metal as processed and aat:300011026 mercury formed, usually in combination with other substances, to make various objects and materials. Refined, dehydroxylated form of the clay mineral kaolinite. Like other pozzolans, it will chemically react with calcium hydroxide at ordinary temperatures to form aat:300386694 metakaolin compounds possessing cementitious properties; and is used as a substitute for cement in some concrete mixtures. Any of a large group of substances that typically show a characteristic luster, are good conductors of electricity and heat, are opaque, can be fused, and are usually aat:300010900 metal malleable or ductile. Rocks that result from the alteration of pre-existing rocks in response to changing environmental conditions, such as variations in temperature, pressure, and mechanical aat:300011437 metamorphic rock stress, and the addition or subtraction of chemical components. The pre-existing rocks may be igneous, sedimentary, or other metamorphic rocks. Interplanetary particles or chunks of stony or metallic maater that survive the passage through the Earth's atmosphere and strike the ground, or that strike any other aat:300266159 meteorites planet. Interplanetary bodies of relatively small size that enter the Earth's atmosphere at high velocity, burn and heat the air around themselves causing a resultant luminous aat:300266160 meteoroids phenomenon that is called a "meteor." If such an object survives its plunge through the atmosphere and lands on the ground, it is called a "meteorite." Colorless, odorless, highly flammable gas, the simplest alkane. Methane occurs in natural gas, as firedamp in coal mines, and is produced by decaying vegetation and in aat:300380535 methane the guts of ruminants. Methane is used as a fuel, and as a starting material in manufacture of chemicals. Methane carried into the stratosphere by rising air acts as a greenhouse gas and degrades the ozone layer. Refers to any methylated derivative of cellulose. Methyl cellulose is a white powder that swells in water and is used as a substitute for natural gums, functioning in aat:300379550 methyl cellulose various commercial contexts as emulsifying, thickening, or sizing agent, lubricant, and suspension aid. In textile and paper conservation, it is used as an adhesive and as a poulticing material for removal of stains. aat:300386625 methyltriethoxysilane An alkoxysilane used as a consolidant in treatment of stone and waterlogged wood. Silane used as a crosslinking agent of silicone rubber and a coupling agent of glass fiber and treatment agents of reinforced plastic laminated product. It is also used as aat:300380181 methyltrimethoxysilane a consolidant in combination with Paraloid B-72 (TM) acrylic resin to treat deteriorated limestones, sandstones, and marbles. aat:300011124 mica (mineral) Group of monoclinic minerals with perfect basal cleavage. aat:300011216 mica diorite Diorite containing appreciable amounts of mica. It can be used for building purposes; many Gothic churches in Brittany have been built of this rock. aat:300011406 micaceous sandstone Sandstone containing mica. aat:300011089 microcline A white, gray, brick-red, or green mineral of the alkali feldspar group. Wax having a fine crystalline structure, comprising the remaining fraction of paraffin wax after the lower molecular weight waxes are removed; it has a higher melting point and viscosity than paraffin, is chemically inert, and a stronger adhesive than paraffin. It can be softened by adding mineral oil or petroleum jelly. Microcrystalline aat:300014605 microcrystalline wax wax does not emulsify easily but can be modified with a catalyst to produce an oxidized, emulsifiable form that is used in hard, self-polishing floor wax. Microcrystalline wax is also used in laminating paper and foils, polishes, waxed paper, adhesives, coatings, linings, and sealants. Microcrystalline waxes were first made in the late 1930s by Baker Petrolite in Barnsdall, Oklahoma. aat:300379441 microfossils Microscopic fossilized remains of organisms usually less than 2mm in size. Subject studied by micropaleontology. aat:300011186 microgranite An igneous rock composed of minute crystals of quartz and alkalic feldspar. aat:300014280 middle oil Polymerized stand oil of increased viscosity, created by heat in the absence of oxygen. Glass made with slices of colored canes embedded in clear molten glass, usually creating flowerlike designs. Distinguish from "mosaic glass" which uses slices of colored aat:300207352 millefiori glass canes as inlays for walls and furniture, beads, jewelry, and to form vessels when arranged in molds and fused together. Naturally occurring inorganic element or compound having an orderly internal structure and characteristic chemical composition, crystal form, and physical properties; aat:300011068 mineral use also for synthetically derived equivalents. aat:300014257 mineral oil A colorless, aliphatic hydrocarbon oil obtained from petroleum distilled at 330-360 degrees C. White, translucent waxy material composed of a series of high molecular weight hydrocarbons, generally obtained from the fractional distillation of petroleum, shale oil, lignite, or coal. Mineral waxes are relatively pure materials that have little to none of the alcohols or esters found in plant waxes and beeswax. Examples of purified aat:300014598 mineral wax mineral waxes are paraffin, ceresin, microcrystalline, and petrolatum, which are stable and unreactive. They are used as a substitute for or extender of beeswax, and in polishes, candles, printing inks, crayons, phonographic records, and insulation. A mineral composed of lead tetroxide that has the same composition as red lead, an orange-red pigment used since ancient times. Minium deposits have been found in aat:300311178 minium (mineral) Egypt, however, most sources indicate that Egyptian red lead pigment was manufactured from lead metal and litharge rather than ground from minium. aat:300010990 minofor Grade of britannia metal containing up to 9% zinc and up to 1% iron. A hydrated mineral form of sodium sulfate, the sodium salt of sulfuric acid, occuring in nature as colorless prismatic crystals near salt water springs or lakes, and in aat:300386826 mirabilite caves. Mirabilite is unstable and quickly dehydrates when exposed to dry air, turning into the powder thenardite. It owes its name to Johann Rudolph Glauber who dubbed it “sal mirabile” (“wonderful salt”) when he inadvertently synthesized it while working with sulfuric acid and salt. It is also known as Glauber’s salt. aat:300011460 mischio marble A coarse breccia marble consisting of white and pink fragments in a darker matrix; it comes from Serravezza, Italy and closely resembles Egyptian breccia marble. aat:300386442 mitridatite Olive colored magnesium-rich secondary phosphate mineral. aat:300212329 modified asphalt Asphalt that has been mixed with additional materials, often non-natural. aat:300212188 modified bituminous material General term for mineral inflammable substances that are native hydrocarbons, more or less oxygenated, that have been altered. aat:300010384 modified portland cement A cement used in general construction where moderate heat of hydration is required. aat:300010497 modular brick Bricks which can be laid to modular dimensions; bricks sized so that the brick plus the mortar joint will form a 4, 8 or 12 inch increment, or module. aat:300055371 moisture Condensed or diffused water. aat:300266703 molasse (rock) Sedimentary rock deposits, consisting mainly of sandstones and shales, formed as shore deposits. Pure metallic element having symbol MO and atomic number 42; a gray silvery metal. Use also for this metal as processed and formed, usually in combination with other aat:300380170 molybdenum substances, to make objects and materials. Refers to a single large block of stone shaped into a pillar, column, sculpture or other item. For modern structural elements composed of cast concrete, use "concrete aat:300265401 monoliths monolith." Mineral wax that is technically a fossilized plant wax, obtained from lignite and peat found in a few deposits worldwide: Amsdorf, Germany, Ione, California, and in the brown coals of Oklahoma and Texas. Its color ranges from dark brown to light yellow when crude, or white when refined. Its composition is non-glyceride long-chain aat:300014599 montan wax carboxylic acid esters, free long-chain organic acids, long-chain alcohols, ketones, hydrocarbons, and resins. It is used as an alternative to carnauba or beeswax in applications such as wood polish, phonograph records, paint, waterproof coatings, adhesives, paper sizing, candles, carbon papers, and insulation. aat:300209721 montmorillonite A dioctohedral clay mineral of the smectite group. Stone, generally of impressive bulk or size, used for erecting any variety of monument, but particularly for tombs or tombstones. The term can also refer to stone used aat:300011717 monumental stone to carve monumental statuary or for constructing monumental architecture. aat:300011090 moonstone An opalescent variety of orthoclase. aat:300266843 moorstone A type of granite found in England, used as a building stone, and often gathered from the surface of moors (hence the name). aat:300011076 morganite A variety of beryl that is rose pink owing to the presence of lithium. Glass made with slices of colored canes which can be used as inlays for walls and furniture, fashioned into beads and various kinds of jewelry, or arranged in molds and aat:300260731 mosaic glass fused together to form vessels. Distinguished from "millefiori glass" which is glass made with slices of colored canes embedded in clear molten glass, usually creating flowerlike designs. Refers to a variety of agate containing brown or black moss- or tree-like dendritic forms. It is typically a grayish to milky-white agate, which is a variety of the silica mineral quartz. It contains opaque, dark-colored inclusions with feathery, branching forms that resemble ferns, moss, or other vegetation but that are in fact of inorganic aat:300264634 moss agate origin, mainly manganese and iron oxides. Most examples of moss agate are found as fragments of weathered from volcanic rocks from India, Brazil, Uruguay, central Europe, and the western United States. The stone has historically been used for ornamental purposes, often cut in flat or rounded forms, and sometimes dyed to improve its color. aat:300011835 mother of pearl Hard, pearly, iridescent internal layer of various kinds of mollusk shell, extensively used for making small articles and inlays. aat:300014337 mud Soil containing so much water that it is soft and at least semi-fluid. aat:300011280 mudstone A clayey mud that has been hardened by pressure of cementation or heat with the composition and texture of shale but is much less fissile. Mineral originally found on the Isle of Mull and used as refractory material for firebrick and furnace linings. It occurs naturally as fused argillaceous sediment inclusions in aat:300212822 mullite the mineral buchite, but this is rare, and as a result, it is produced artificially. Epoxy resins that exhibit a degree of crosslinking higher than that of standard difunctional resins and that possess adhesive characteristics. Multifunctionality arises as a aat:300014537 multifunctional epoxy result of N-glycidyl, O-glycidyl and N- and O-glycidyl groups in the resin structure. A strata of limestone chalk formed from shell deposited in the Middle Triassic formation. Found in Europe, most commonly in Germany, lying above the Bunter and and aat:300265606 muschelkalk below the Keuper layers. aat:300011125 muscovite (mica) A colorless or pale brown mica; it has superior dielectric properties and is valued for radio capacitators. Pungent yellow powder of the seeds of any of several common mustard plants, used as a condiment, dye, or in medicine as a stimulant and diuretic, an emetic, or a aat:300311365 mustard (material) counterirritant. Vegetable oil obtained from mustard seeds, characterized as a nondrying oil primarily used in food products, medicines, and a plasticizer with drying oils and with natural aat:300014322 mustard oil and synthetic resins. Aromatic, yellow gum resin obtained from various African, Arabian, and Indian trees of the Commiphora genus. Myrrh contains approximately 25% resin (mostly aat:300380203 myrrh triterpenoids), 60% gum, and 15% volatile oils. Translucent yellow resins have been used for incense and perfumes since ancient times. Myrrh has also been used for its healing properties in traditional medicines. aat:300380449 nannofossils Nannofossils are microfossils with a diameter less than 50 microns; one micron being equal to one millionth of a meter. aat:300380210 nanocomposite A composite material whose grain size is measured in nanometers. Calcium hydroxide particles with submicrometric dimensions synthesized by a chemical precipitation process. The nanoparticles dispersed in ethanol have been used as a aat:300387679 nanolime conservation treatment for consolidating calcareous historic materials damaged by water uptake. A crystalline aromatic compound (C10H8) derived from coal tar, with a molecule consisting of two fused six-membered rings and a pungent mothball smell, used in dyes, aat:300311489 naphthalene (bituminous material) synthetic resins, explosives, insecticide, fungicide, and moth repellent. It is not recommended for general use as an insecticide because it may recrystallize on specimens and can discolor wool in the presence of moisture, and its actual effectiveness against insects is questionable. It fluoresces purple in mercury light. aat:300310958 nashiji urushi A highly translucent or transparent lacquer that has an amber or orange tint. It was made by mixing ki urushi with gambodge or the sap of the Gardenia florida. Hydrous sodium carbonate found in nature as evaporative residues. Used widely as a silica source in early glass manufacture; in ancient Egypt used as well as a bleach aat:300379923 natron for linen, a preservative in mummification, and as an ingredient of incense. Asphalt found in natural deposits, as distinguished from asphalt formed as a residue from the distillation of petroleum. Natural asphalt is found where crude oil seeps aat:300375653 natural asphalt from the ground. It was formed during an early stage in the breakdown of organic marine deposits into petroleum. It characteristically contains minerals, while residual petroleum asphalt does not (although minerals may be added). aat:300212198 natural bituminous material General term for natural, mineral inflammable substances that are native hydrocarbons, more or less oxygenated, and which have not been modified. aat:300010369 natural cement Cement produced by taking finely pulverizing calcined argillaceous limestone and heating it to complete decarbonation, which is the process of removing carbon dioxide. General term for materials obtained from excretions from certain trees or shrubs. Natural resins are aromatic hydrocarbons that are generally soluble in alcohol or aat:300378966 natural resin turpentine and insoluble in water. The shell of the pearly nautilus, Nautilus macromphalus, native to the tropical Pacific and Indian Oceans, used to make decorative objects such as cups, salts, and aat:300261383 nautilus shell jewelry, and as carving material. aat:300263786 naval brass (tin brass type) A type of tin brass that is widely used for products requiring high strength and a high level of corrosion resistance, particularly marine equipment. aat:300012998 navy pitch Substance obtained by melting rosin with pine tar. aat:300010413 neat cement In masonry, a pure cement uncut by a sand mixture. Pale yellow, faaty oil made from boiling the shinbones and heels of caatle; used to dress leather and as a lubricant. In conservation, used to restore the elasticity of aat:300387024 neat's-foot oil leather. aat:300180393 neon Inert gaseous element with symbol Ne and atomic number 10; used as the medium in some electric discharge lamps. Synthetic rubber made by polymerization of chloroprene and characterized by superior resistance to oil, gasoline, sunlight, ozone, and heat, and by lower permeability to aat:300014387 neoprene gas than rubber. An exceptionally tough, compact, fine-grained greenish or bluish mixture of actinolite and tremolite; it is a calcium magnesium silicate with traces of chromium and nickel, which produce its color. With jadeite, it is one of two minerals commonly called "jade." Nephrite has an oily, lustrous appearance when polished and is sometimes aat:300011120 nephrite variegated in color that can incorporate white, yellow, brown, gray, and black. Nephrite has been used since Neolithic times for small utensils, decorative carvings and jewelry. If heated to about 1025 C, nephrite changes mineral forms to diopside. aat:300011492 nero antico An ornamental black marble found in fragments among Roman ruins and believed to have come from Laconia. Pure metallic element having symbol Ni and atomic number 28; a silvery white metal with a yellowish cast, resistant to corrosion and to most acids except nitric. Use aat:300011028 nickel (metal) also for this metal as processed and formed, usually in combination with other substances, to make various objects and materials. aat:300010933 nickel alloy Any alloy containing nickel as the base metal, or as the chief alloying element. aat:300133207 nickel bronze Bronze that contains nickel, usually replacing part of the tin content, to produce a tough, fine-grained, corrosion-resistant metal. Alloy of copper, nickel, and zinc, the nickel serving to enhance color. Uses include operations that require ductility in the cold state, such as stamping, spinning, deep aat:300242125 nickel silver drawing, and for articles to be plated. Steel with nickel as the dominant alloying element; the addition of nickel can result in steel that is less likely to warp or crack, more resistant to corrosion, and generally aat:300010927 nickel steel stronger and harder. aat:300380228 niobium Metallic element having symbol Nb and atomic number 41, formerly named columbium; soft grayish-white transition metal used in superconducting alloys. aat:300380540 nitride A compound in which nitrogen is paired with a more electropositive element, such as silicon, boron, and most metals. aat:300014389 nitrile elastomer An oil-resistant synthetic rubber or copolymer of acrylonitrile and butadiene used in such applications as oil well parts, gaskets, rollers, or fuel hoses. aat:300380348 nitrite Refers to any salt or ester of nitrous acid. Substance comprising a mixture of nitric esters of cellulose and a highly flammable compound containing more than approximately 12.5 percent nitrogen. Nitrocellulose is a fluffy white substance that retains some of the fibrous structure of untreated cellulose. It is not stable to heat and will ignite easily. It was first introduced in the 19th aat:300014444 nitrocellulose century as an explosive. It was used to produce animation cels for 80 years until acetate was introduced as a safer medium in the 1950s. Cellulose nitrate was often used for clear lacquers, fabric dopes, adhesives, high-gloss paints, and mixed with natural resins (dammar, shellac, copal, etc) to create a waterproof varnish. Cellulose nitrate is inherently unstable and slowly decomposes at room temperature. An element with atomic number 7 and symbol: N. It is an odorless, gaseous element that makes up 78% of the earth's atmosphere, is a constituent of all living tissue, aat:300266339 nitrogen and is nearly inert in its gaseous form. aat:300210801 nitrogen compounds Substances composed by the chemical union of nitrogen with additional elements. A toxic and reactive reddish gas, NO2, nitrogen dioxide is an atmospheric pollutant (as in photochemical smog) produced by combustion of fossil fuels. Exposure to aat:300379677 nitrogen dioxide nitrogen oxide can cause fading of dyes and organic colorants in paints, textiles, and photographs, as well as deterioration of calcareous stone. Used in an ecological context to describe a large class of nitrogen oxide gases produced in combustion which occur as atmospheric pollutants. Colorless, poisonous gas formed when nitric acid reacts with copper or when ammonia reacts with platinum. It is produced in combustion engine processes such as automobile emissions, aat:300379632 nitrogen oxides resulting in acid rain and photochemical smog. It is also an important messenger molecule in mammals and other animals, produced through cellular metabolism, and involved in oxygen transmission, blood pressure regulation, and other physiological activities. A colorless, sweet-smelling, sweet-tasting, non-flammable, slightly water-soluble gas, N2O. It is used chiefly as an anesthetic in dentistry and surgery, and in the aat:300011768 nitrous oxide manufacture of chemicals, such as aerosols. aat:300010783 no-fines concrete A lightweight concrete mixture containing little or no fine aggregate. Metal or alloy that is resistant to oxidation, corrosion, and dissolution by acids. Noble metals remain bright when heated in air. Examples of noble metals are gold, aat:300241621 noble metal iridium, mercury, osmium, platinum, and ruthenium. In physics, noble metals are restricted to those having filled electronic d-bands: according to this definition in physics, only gold, silver, and copper are noble metals. Many noble metals are also precious metals, due to their rarity in the Earth's crust. Non-hydraulic lime is a slower setting low cost alternative to hydraulic lime. Whereas hydraulic lime sets by hydrolysis (chemical reaction with water), non-hydraulic aat:300386962 non-hydraulic lime lime, also known as 'air lime', sets by carbonation. It needs air to carbonate and thus set. Unlike hydraulic lime, which is powder derived from lime stone containing impurities, non-hydraulic lime is drawn from pure calcium lime stone and turned into a putty through a process of high temperature heating, slaking, and maturing. aat:300014317 nondrying oil Oil characterized by lower iodine values. These oils will remain viscous within a range of moderate temperature indefinitely. aat:300010784 normal-weight concrete Concrete having a unit weight of approximately 150 pounds per cubic foot, made with aggregate of normal weight. Any of a variety of thermoplastic polymers originally developed as textile fibers and used in fabrics. They have a straight-chain polyamide structure and are largely heat- aat:300014462 nylon resistant. Developed in 1939 at I.G. Farbenindustrie (which marketed it as Perlon), nylon 6 was developed as a dyable, durable nylon fiber intended to compete with DuPont's aat:300387481 nylon 6 nylon 6,6. It is very similar but has a lower melting point and a greater affinity for dyes. The two types of polyamide fiber remain the most commonly used by the textile and plastics industries worldwide. It is formed by polymerizing caprolactam under high pressure and is thus also known as polycaprolactam. A durable, dyable nylon fiber formed from hexamethylenediamine and adipic acid. Nylon 6,6 was developed at DuPont in 1935. It is very similar in structure to nylon 6, a aat:300387482 nylon 6,6 rival product created ny I.G. Farbenindustrie four years later, and the two types of polyamide fiber remain the most commonly used by the textile and plastics industries worldwide. A dark, shiny glass formed in nature by the rapid cooling of lava. Obsidian is widely distributed and has been used since Paleolithic (before 3500 BCE) times for mirrors, weapons, tools, and jewelry. Obsidian is often black in color but may also be red, brown or green. It produces conchoidal fractures when cleaved. Sources of obsidian aat:300011254 obsidian include Anatolia, Armenia, Ethiopia, Greece (Milos), Italy (Lipari, Eolie), Iceland, the U.S. (Wyoming), Mexico (Teotihuacan), Guatemala (Tikal), and Peru. Obsidian changes into pumice when it is melted. A shell marble which is usually either light purple or reddish brown in color. Its name means 'peacock's eye' in Italian, the eye referring to the presence of petrified aat:300011480 occhio di pavone oyster shells. There are two columns made of this marble in the Vatican Library. aat:300386636 odontolite Fossil bone or tooth consisting of the phosphate mineral fluoroapatite colored blue by vivianite. It is used as a gemstone closely resembling turquoise. Any greasy substance that is liquid at room temperature and insoluble in water. Fixed (nonvolatile) oils have the same chemical composition as fats: they consist chiefly aat:300014254 oil (organic material) of glycerides, resulting from a reaction between glycerol and faaty acids. Oils may be divided by function and type: mineral (e.g., paraffin), vegetable (e.g., linseed), animal (e.g., fish), essential (e.g., turpentine), or edible (e.g., olive). aat:300183853 oil of cedar Essential oil used for its effects on spirit varnish and for its ability to retard the drying of paint. An essential oil obtained from the dried flower buds of clove tree (Eugenia caryophyllata or Syzygium aromaticum), containing eugenol along with carophyllin, tannin, aat:300014261 oil of cloves gum, and resin. Used as an additive used to retard the drying of paint. Oil-modified alkyds made with 30-45 percent added oil are called short-oil alkyds and are often used in baked enamel finishes on metal objects. Oil-modified alkyds with aat:300044085 oil-modified alkyd 56-70 percent added oil, called long-oil alkyds, are typically used in commercial paint formulations and varnishes. aat:300014297 oiticica oil A drying oil obtained from the kernel of the fruit of the oiticica tree that is similar to tung oil; used chiefly in varnish, paint, and printing ink. aat:300014323 olive oil Vegetable oil extracted from the ripe fruit of olive trees, and used mainly for food and cooking oil. A magnesium iron silicate mineral characterized by an olive green color, occurring in igneous and metamorphic rocks. It has two compositional varieties: fayalite (iron aat:300147980 olivine rich) and forsterite (magnesium rich). The opaque variety of the stone was found in Egypt, in the lava of Vesuvius, and in the Eifel district of Germany. Transparent, gem quality stones are called peridot, and found in various locations around the world.Olivine beads have been found in pre-Dynastic Egyptian jewelry. A variety of chacedony having parallel, alternating bands of chalcedony and opal. The bands are usually colored black and white or reddish and white. In ancient times, aat:300011136 onyx (mineral) the stones were available in Egypt, Arabia, and India. Onyx was often used as a gemstone in the production of cameos and intaglios. Onyx is also used as an ornamental building stone and for decorative items such as table tops, lamp bases, and small boxes. Term used in the glass trade for a glass made to resemble onyx either by the addition of metal and metallic oxide that impart a silver luster upon heating, or by mixing aat:300207341 onyx glass glass of contrasting colors. A compact variety of calcite that has dark layers of impurities and polishes to a high gloss, resembling onyx in appearance. It is typically used as a decorative or aat:300011337 onyx marble architectural material or for small ornamental objects. aat:300011310 oolite Rock consisting of small round grains that are cemented together and consist usually of calcium carbonate, but are sometimes of silica or iron oxide. aat:300133209 oolitic limestone Limestone containing many small, rounded particles, which are concentric layers of calcium carbonate deposits. aat:300011129 opal A mineral or mineral gel consisting of packed spheres of silica. Used as a gemstone, it is characterized by a flashing mixture of colors when light falls on the surface. Bluish white, fiery, opalescent, translucent glass that has been made white by the addition of calcium phosphate (bone ash) and opalescent by the addition of fluorides aat:300129184 opal glass (fluorspar, cryolite, or lepidolite) and/or arsenic. Red tones appear in transmitted light. Opal glass was used for windows, bowls, light shades, table tops, and cosmetic jars. aat:300386526 opaque red glass An opaque glass whose red color is generally caused by cuprous oxide crystals. aat:300210944 opaque white glass An opaque glass that has the appearance of white porcelain. aat:300010877 optical glass A highly refined glass, usually a flint glass of special composition, or made from rock crystal, used for lenses and prisms. aat:300375411 orange oil Essential oil obtained from the rind of the orange and used in perfume, as flavoring, in herbal medicine, cleaning products, insecticide, and as an appetite suppressant. aat:300014920 orange shellac Manufactured product of stick lac, the secretion of Laccifer lacca kerr. aat:300013578 orange vermilion (pigment) A term sometimes applied to the more yellowish kinds of vermilion. aat:300010389 ordinary portland cement A cement, without any of the distinguishing characteristics of the other types of portland cement, that is used for general construction purposes. Naturally occurring material from which mineral can be extracted; the term is generally but not always used to refer to metalliferous material, and is often modified by aat:300152583 ore the name of the valuable constituent, for example, iron ore. aat:300011792 organic material Material containing carbon, including those derived from living organisms. aat:300391386 organic sulfide Compounds in which sulfur is bonded to two organic groups. aat:300390570 organically modified silica Silicates organically modified by the sol-gel process. In conservation, applied as protective coatings for stone and stained glass. aat:300212574 organometallic compound A compound comprised of a metal aatached directly to a carbon. Brass (a copper-zinc alloy) that is rich in zinc; it is easy to cast, is ductile, and has a golden color. It was notably used by the ancient Greeks and Romans. According to legend, it was mined in Atlantis in ancient times. It used for jewelry and, according to Plato, to line the outer walls of the Temple to Poseidon on Atlantis. By Roman aat:300195994 orichalcum times, the alloy was used for coinage and jewelry. It is likely that references to the material have historically referred to various yellow metals or alloys, for example, perhaps to a naturally occurring alloy of copper and gold. aat:300011048 ormolu Brass or bronze which is gilded or is gold in color. aat:300011091 orthoclase A white, pink, or gray mineral of the alkali feldspar group. aat:300255937 ossein The collagen in bone; used to make glue and gelatin. aat:300192945 osteocalcin The calcium-binding protein in bones. aat:300379572 oxalate A salt or ester of oxalic acid. aat:300010414 oxychloric cement A strong, hard cement made of calcined magnesia and magnesium chloride. With various fillers, it is often used for stucco and floors. aat:300266782 oxygen Nonmetallic chemical element (O). It is a colorless, odorless, tasteless gas, the most plentiful element in the Earth's crust; its most important compound is water. aat:300011836 oyster shell Shell of an oyster. Light yellow to dark brown waxy mixture of paraffinic hydrocarbons found in rocks in Utah, Galicia, Australia, and Romania near the Caspian Sea. It is used as a substitute for beeswax and carnauba wax in polishes, candles, printing inks, crayons, sealing waxes, phonograph records, and insulation. It is also used for leather aat:300014600 ozokerite (ozokerite) polish, lithographic and printing inks, carbon paper, floor polishes, waxed paper, and textile sizing. For ozorite that has been purified by boiling and alkali treatments, use "ceresin." An allotropic form of oxygen, O3, which is a bluish toxic gas with a characteristic sharp odor, is a powerful oxidizing agent, and is produced from molecular oxygen by aat:300266796 ozone electrical discharge and in the upper atmosphere by ultraviolet light. Region of the ozone layer in which the ozone concentration is substantially depleted, occurring chiefly at high latitudes and aatributed to the chemical action of CFCs and aat:300266799 ozone hole other atmospheric pollutants. Region of the upper atmosphere of the Earth containing a relatively high concentration of ozone, which absorbs much of the ultraviolet radiation reaching the earth from aat:300266797 ozone layer the sun. aat:300011470 pagoda stone A Chinese marble with markings created by fossil content; when the stone is cut sectionally, the markings resemble the shape of a pagoda. aat:300242126 paktong (material) An alloy of 45% copper, 30% nickel, 24% zinc, and 1% iron, resembling German silver, first used by the ancient Chinese. It is light, hard and ideal for casting. A yellow or brown-colored siliceous alteration product resulting from the hydration of basaltic volcanic glass that has undergone rapid chilling. It is found as pyroclastic aat:300386696 palagonite cones in areas where basaltic eruptions come in contact with water, as in the Galapagos Islands. Pure metallic element having symbol Pd and atomic number 46; a rare, lustrous silvery white metal found in platinum ore. Use also for this metal as processed and aat:300011030 palladium formed, usually in combination with other substances, to make various objects and materials. A thin, beaten leaf used in gilding for a silvery effect. It is often used as a replacement for silver leaf because palladium, a precious metal that is part of the platinum aat:300265200 palladium leaf group of elements, does not tarnish at normal temperatures. Palladium leaf is slightly duller in appearance than silver leaf. Plant oil extracted from the mesocarp of the fruit of some palms, particularly the West African oil palm (Elaeis guineensis). The outer fleshy portion of the fruit is aat:300390962 palm oil steamed to destroy the lipolytic enzymes and then pressed to recover the palm oil, which is highly coloured from the presence of carotenes. Palm oil is used in making soaps, candles, and lubricating greases and in processing tinplate and coating iron plates. A white marble from ancient Phrygia (present-day Turkey); it is usually ivory or milky white and sometimes contains shell fragments or faint gray or chocolate brown aat:300011592 palombino spots. It is rarely found in large blocks but was often used as tiny square chips in ancient mosaics. aat:300010562 pamment Tile or brick used for paving a malthouse floor. aat:300010712 pan-and-roll roofing tile Single-lap roofing tile of two types used in combination: a flat, tapered undertile having flanges, and a half-rounded, tapered overtile. In ancient architecture, a term used to describe a flat tile or tegula. In modern usage, an S-curved roofing tile, laid so the down curve of one tile overlaps the up curve aat:300010713 pantile of the next one. A type of Numidian marble that is white or yellow with purplish veins; it resembles pavonazetto marble which has led scholars to believe the name is a corruption of aat:300011561 paonazzo marble 'pavonazetta.' A viscous, oleoresin obtained from South American deciduous trees of the genus Copaifera native to Brazil, containing 60-90% copaiba oil. A viscous, oleoresin obtained aat:300012902 para balsam from South American deciduous trees of the genus Copaifera native to Brazil, containing 60-90% copaiba oil. Colorless to white, translucent, flammable, hard wax of straight-chain hydrocarbon residue distilled from petroleum and shale, ranging in melting point from about 48-66 degrees C (120-150 F). Paraffin wax is obtained from petroleum by dewaxing light lubricating oil stocks; it was first produced commercially in 1867. It is used in candles, aat:300014603 paraffin (wax) wax paper, polishes, cosmetics, sealing, and electrical insulators. It assists in extracting perfumes from flowers, forms a base for medical ointments, and supplies a waterproof coating for wood. In wood and paper matches, it helps to ignite the matchstick by supplying an easily vaporized hydrocarbon fuel. General term for any of several viscous hydrocarbon oils, including the oil pressed from paraffin wax. Paraffin oil is sold in several grades and ranges in color from brown aat:300183861 paraffin oil to yellowish brown with a pronounced bluish bloom. Debloomed paraffin oil is pale gold in color and is used as higher-grade polishes and as household lubricating oil. Yellow surface coating of friable material that forms on unprotected realgar exposed to light; this light-induced transformation product is found occasionally in paintings aat:300380237 pararealgar in association with the pigment. In the past, pararealgar has been confused with the pigment orpiment to which this sulfide arsenic mineral is closely related. Paratacamite is a basic chloride of copper sometimes used as a green pigment in painting. In a conservation context, its presence as a deposit on bronze and copper aat:300380023 paratacamite artifacts indicates bronze disease. Variety of porcelain material comprising a soft or hard paste, white, fine, and vitreous, often resembling statuary marble; developed in England in the 1840s and used aat:300219039 parian (porcelain, material) for figurines, especially dolls, and for art objects, ornament, and tableware. For unglazed porcelain or earthenware that has been fired only once and used for similar types of objects, but producing a grainy texture, use "biscuit (porcelain, material)." aat:300011511 parmazo marble A marble of Northern Italy having a coarse network of dark veins on a white or grayish ground. aat:300010697 partition tile Tile for use in building interior partitions, subdividing areas into rooms, or similar construction, carrying no superimposed loads. aat:300010803 paste (glass) A brilliant glass of high lead content used for the manufacture of artificial gems; also an imitation gem made of this material. aat:300012987 paving asphalt Natural or modified asphalt or an asphalt aggregate intended for use as a binder in asphalt concrete. aat:300014347 paving sand A building sand graded for three separate purposes: concrete pavement, asphalt pavement, and grouting. aat:300011718 paving stone A block or chunk of stone that is shaped or selected by shape for a paved surface. A white or drab yellow marble with purplish veins, it was supposedly favored by the emperor Hadrian. The word pavonazzo means peacock blue, violet, or purple in aat:300011562 pavonazzetto Italian. The ancient marble is also known as Phrygian marble because it is believed to have come from Phrygia in Asia Minor. aat:300011690 pea gravel Small-diameter (6.4 to 9.5 mm or 1/4 to 3/8 in.) natural gravel, screened to specification. aat:300207345 peach blow glass Trade name for an art glass made to imitate the appearance of the peach-bloom glaze on Chinese porcelain. aat:300014324 peanut oil Vegetable oil extracted from the seed kernel of the peanut. The oil is edible and used for cooking, but is also used in soaps and fuels. A smooth round bead formed primarily within the shells of two distantly related groups of molluscan bivalves or clams, including the ocean-dwelling pearl oysters and aat:300011827 pearl (animal material) the freshwater river mussels. Pearls are used in jewelry and for other ornamental puposes; they are considered a gem. aat:300014340 peat An unconsolidated deposit of semicarbonized plant remains formed in a water-saturated environment such as a bog. A rock fragment, generally rounded by abrasion, larger than a granule and smaller than a cobble; it has a diameter in the range of 4 to 66 mm, or a size between that of aat:300011691 pebble (rock) a pea and that of a tennis ball. A generic term for a group of polysaccharides that are located in the cell walls of all plant tissues. Pectin is composed of methoxylated galacturonic acids joined in long aat:300266453 pectin chains. The main commercial sources of pectin are citrus peel and apple pomace. Pectin dissolves in water to produce viscous stable solutions. They are mainly used for food products (jams and jellies) but are also found as sizing agents in paper and textiles. aat:300011187 pegmatite A coarse-grained igneous rock, largely granite, sometimes rich in rare elements such as uranium, tungsten, and tantalum. aat:300013009 pentane Any of three types of isometric paraffin hydrocarbon found in petroleum and natural gas. Ash, gravel, and volcanic material that have been closely welded together to form a rock that is characteristically dark greenish gray and studded with black fragments aat:300011265 peperino that resemble peppercorns, hence its name. It is used for stairs and fountain bases because it becomes more consistent when wet. Susceptible to heat and frost, it is only found in great condition underground. Quarries for this rock are found near Albano and the Castle of Marino in Italy. aat:300010524 perforated brick Brick with vertical perforations or holes; the addition of holes decreases the weight of the brick without significantly reducing its strength. The transparent, gem-quality variety of olivine, which is a magnesium iron silicate mineral characterized by an olive green color. Peridot was known in ancient Greece and in Egypt; many of the green stones known to be worn by Cleopatra were peridot. Peridot was called "evening emerald" because it appears to lose its yellowish cast aat:300311371 peridot (mineral) at night. It has sometimes been misidentified as emerald and as green glass. The main old world source for peridot was the island of Zabargad on St. John's Island in the Red Sea. It is also found in Brazil, South Africa, Myanmar, Norway, British Columbia, and Arizona and Hawaii in the USA. aat:300014298 perilla oil Drying oil used in house and industrial paint, linoleum, and printing ink. A volcanic glass that contains about 75% silica and usually has a higher water content than obsidian; found in Oregon and California. Commercially, the term refers to aat:300011257 perlite volcanic glass that will expand or "pop" when heated to form a lightweight aggregate. aat:300013011 petrochemical A chemical compound obtained or derived industrially from petroleum or natural gas. Complex mixture of hydrocarbons that occurs naturally beneath the earth's surface, viscous yellow to black in color. Petroleum is refined (i.e.,separated by distillation) aat:300013001 petroleum into useable fractions. aat:300012970 petroleum asphalt Asphalt obtained from the refining of petroleum; the heavier or more viscous portions of certain crude oils are asphalts. aat:300249810 petroleum ether A volatile flammable petroleum distillate often used as an extracting agent for soft resins, oils, and waxes. aat:300013013 petroleum jelly A soft, greasy, translucent, semi-solid mixture of hydrocarbons, obtained from petroleum and used as an ointment and lubricant. aat:300010979 pewter (tin alloy) Alloy of tin and various proportions and combinations of lead and antimony, and sometimes also copper. Refers to any of a large class of synthetic resins made by reacting phenol with formaldehyde. Phenolic resins were the first totally synthetic polymers to be aat:300014540 phenolic commercialized. Bakelite is a phenolic plastic. Current industrial applications include adhesives in plywood. aat:300011126 phlogopite A magnesium-rich mineral of the mica group; it is usually yellowish brown to brownish red and usually occurs in crystalline limestone as a result of dedolomitization. Rare mineral that occurs as pale yellow crystals. Phosgenite is formed in the oxidation zone of lead ore deposits. Phosgenite has been identified as a constituent in aat:300380546 phosgenite ancient Egyptian cosmetic powders; it appears to have been synthetically produced using “wet” chemistry. aat:300379779 phosphate An ester or salt of phosphoric acid. aat:300391388 phosphine sulfide Sulfides that occur when the sulfur atom reacts with organic phosphines. Bronze containing phosphorus, or which has been deoxidized by the addition of phosphorus in its final processing stage, little or no phosphorus remaining in the final aat:300010961 phosphor bronze alloy. Formerly, the term referred to a non-crystalline or fibrous form of apatite. In current usage, it is a general term referring to any sedimentary rock containing a high aat:300390982 phosphorite proportion of calcium phosphate. aat:300192803 phosphorus An element with symbol P and atomic number 15. aat:300183863 photographic gelatin Gelatin that is chemically purer and physically more refined than food-quality gelatin and is used as the binding medium in some photographic emulsions. Clear silicate glass that will form permanent three-dimensional color photographic images when subjected to x-rays or ultraviolet light through a negative. Photosensitive aat:300010878 photosensitive glass glass contains submicroscopic metallic particles; the high energy causes the particles to precipitate out of solution. The image is fixed by heating the glass to 540 C. aat:300011622 phyllite Refers to a type of rock consisting of clayey, or argillaceous, slate or schist containing scales or flakes of mica. Plant trace fossils, microscopic mineral particles secreted by plants which are highly resistant to deterioration. Phytoliths can be a source of important palaeobotanical aat:300379628 phytoliths information. aat:300379846 pietra d'Oggiono Bluish sandstone used as a building material; quarried near the towns of Oggiono and Sirone in Lombardy, Italy. aat:300379832 pietra di Lecce A creamy white or golden colored limestone dating from the Miocene period that is quarried in Lecce, a city in the Salento region of South East Italy. aat:300379839 pietra di Mendicino Calcareous tufa stone used for building and sculptural decoration originating in quarries near the town of Mendicino in Calabria, Italy. An easily worked yellow-brown fossiliferous limestone quarried in the Berici Hills south of Vicenza. It has been used since ancient times as a building and ornamental aat:300379847 pietra di Nanto stone; the cathedral of Padua is a pietra di Nanto construction. aat:300379838 pietra di Prun A durable, fossiliferous limestone quarried near Verona, Italy; used as a building material since ancient times. aat:300379840 pietra di San Lucido Beige colored limestone used as a building and construction material quarried near town of San Lucido in province of Cosenza, Calabria, Italy. aat:300379850 pietra di Verona A red colored limestone quarried near Verona, Italy from the "Rosso Ammonitico Veronese" formation; used as a construction material in buildings and monuments. aat:300379836 pietra di Vicenza Porous, fossiliferous limestone, yellowish white in color, quarried near Verona, Italy; used as a construction material. aat:300011224 pietra di paragone An extremely hard variety of basalt that is jet black in color with a faint steak of mottled white; was often used as a touchstone for metallurgists. An extremely heavy sepentinite having the form of a flaatened sphere, its name deriving from the Greek word for kidney. The rocks were used by the ancient Romans as aat:300011632 pietra nefritica standard weights and were also supposedly tied around the necks of condemned Christians before they were drowned, explaining why it is sometimes referred to as martyr's stone. It is most commonly jet black with small specks of gray and a metallic texture. Refers to several groups of greenschist found in the Italian Central Alps which contain carvable soapstone; much used in the Middle Ages as a material for the production aat:300379843 pietra ollare of food preparation and storage vessels, and of stoves. A honey-brown calcareous sandstone quarried in Fiesole and other locations in the vicinity of Florence, where it is used as a building stone. The Ponte Vecchio, Pitti aat:300379815 pietraforte Palace, and Palazzo Vecchio are all pietraforte constructions. A brick for constructing pilasters or slightly projecting piers, the end of which is so notched or rebated that it bonds more readily with the backing, thus increasing the aat:300010564 pilaster brick stiffening of the wall. An alloy of about five parts of copper with one of zinc that is used as imitation gold. It is similar to brass but contains more copper. It was invented by a London aat:300265141 pinchbeck watchmaker named Christopher Pinchbeck, ca. 1740. Pinchbeck was often used in clock making and the production of inexpensive jewelry and snuffboxes, particularly by craftsmen in London. Vegetable oil derived from the seeds of the European Pinus species, especially Pinus pinea. Early written works on painting aatest that pine seed oil was used as a drying aat:300386445 pine seed oil oil by Spanish painters. aat:300012996 pine tar Wood tar produced by distilling pine wood, used in wood preservatives and medicinal products. aat:300011202 pink granite Granite with a mineral composition that results in a pink color. aat:300011520 pink marble Marble with a mineral composition resulting in a predominantly pink color. aat:300207383 pink-slag glass Term used in the glass trade for a type of art glass molded in ornate paaterns, made in various shades of pink. aat:300180681 pipe clay A type of fine white clay used to make tobacco pipes and fine earthenwares. A coarse-grained limestone composed mainly of cemented pisoliths, which are pea-sized accretionary bodies, often formed of calcium carbonate, that may have been aat:300011327 pisolitic limestone produced by a biochemical algal-encrustation process; pisoliths are larger and less regular in form than oöliths. aat:300014362 pisé A building material consisting of stiff earth or clay forced in between forms. A sticky, black residue obtained from the distillation of coal tar, petroleum, or pine tar. Pitch is used as a sealant and wood preservative as well as a component in aat:300012949 pitch (tar) roofing, paving, and water proofing. aat:300010616 place brick Inexpensive, red soft brick used as building brick rather than as face brick. aat:300011092 plagioclase A group of triclinic feldspar distinguished from alkali feldspars which are sodium- or potassium-rich. In physics, plasma is an electrically conductive gas of low density, affected by magnetic fields. It is fully ionized and contains approximately equal numbers of positive aat:300379490 plasma and negative ions. A general term for any of a large and varied class of natural or synthetic organic materials that can be molded, extruded, or cast when soft or liquid, and then set into a aat:300014570 plastic (organic material) rigid or slightly elastic form. Natural plastics include tree resins, beeswax, gutta-percha, horn, and clay. Synthetic plastics were first made in the 19th century. Plastics are used widely in manufacturing. aat:300014572 plastic alloy Alloys created between two or more thermoplastic resins to allow resin polymers to be blended that cannot be polymerized. Lightweight and buoyant polymers containing uniformly dispersed air pockets, like a sponge. They are made from most types of polymers (rubber, polyethylene, polystyrene, epoxy, polyurethane, vinyl resins, silicone resins, and others). Steam, air or an inert gas is mechanically added or chemically produced in the plastic resins aat:300014565 plastic foam during manufacture to form a cured open cellular structure. They may be soft and spongy (foam rubber, polyethylene, etc.) or rigid and strong (polystyrene, epoxy). Closed-cell foams have individual non-connected bubbles while open-cell foams have an interconnected tunnels formed when the incorporated gas or steam escapes during cure. Resin-impregnated materials, such as paper or fabric, produced under heat and high pressure to form an insoluble homogeneous piece. Laminates were first made in aat:300014579 plastic laminate 1907 by Leo Baekeland when he coated canvas with phenol formaldehyde. Distinguished from "laminated plastic" which is a thin sheet of superimposed layers of plastic bonded or impregnated with resin and compressed under heat. aat:300179430 plastisol Colloidal vinyl resin dispersed in liquid plasticizer, which will form into a solid with the application of heat. Commonly used as a coating for metal or cloth. Generally, a layer of metal deposited upon a metal base, for purposes of decoration or to impart desirable physical or chemical properties. Distinct from "plate (object aat:300011041 plate (material) genre)" which refers to objects made of high quality solid silver or gold. The term is used more correctly for silverwork alone, but sometimes used loosely for goldwork as well. aat:300010822 plate glass Any glass that has been rolled or cast into a sheet and then ground and polished. aat:300263377 plated metal Metal composed of two or more layers of different metals joined to each other by plating and without being fused into a homogenous mass as in an alloy. Pure metallic element having symbol Pt and atomic number 78; a lustrous, malleable, ductile, silvery white metal, considered a precious metal. Use also for this metal as aat:300011031 platinum (metal) processed and formed, usually in combination with other substances, to make objects and materials. Naturally occurring mineral form of lead dioxide; black crystals or blackish brown masses. In mural paintings, lead-based pigments may convert to plaatnerite over time, aat:300386446 plaatnerite causing deterioration and blackening to the pictorial surface. aat:300010503 plinth brick A brick beveled on its face or end to provide for the reduction in thickness between the plinth and the main part of a wall. aat:300014431 polyacrylate A polymer of acrylic acid. A polymer made from the addition polymerization of acrylonitrile. Polyacrylonitrile was first made in the late 1930s and it quickly became an important type of synthetic aat:300250693 polyacrylonitrile rubber. aat:300014469 polyamide Thermoplastic polymer group which includes nylon and other synthetic resins. A class of elastomers that is notable for performance at low temperatures, resilience, and abrasion resistance. Used for shoe heels and soles, gaskets, and belting. aat:300014395 polybutadiene elastomer Combined with other rubbers to improve their resilience and flexibility at low temperatures. aat:300014471 polybutylene Thermoplastic polymer of butylene, formerly used for water pipes. aat:300014473 polycarbonate Thermoplastic polyester used in glazing, including bullet- and explosion-resistant laminates. Any of a class of low molecular-weight synthetic varnish resins, also known as ketone resins, composed of polymerized cyclohexanone and/or methyl cyclohexanone and aat:300380075 polycyclohexanone widely used for picture varnishes. aat:300014546 polyester (resin) Resin formed by the reaction between dibasic acid and dihydroxy alcohol. Amorphous, high-temperature, yellowish or transparent thermoplastic developed in 1982 with a molecular weight of Tg = 215C. Characteristics include resistance to aat:300014481 polyetherimide ultraviolet and gamma radiation. May be used as reinforcing fiber or as fire-resistant material in electrical components, jets, and automobiles. Resistant to aliphatic hydrocarbons, alcohols, and dilute bases. aat:300014396 polyethylene elastomer Polymeric substance prepared from derivatives of ethylene that are capable of recovering their original shape after being stretched to great extents. Thermoplastic polymer of the polyester family made by condensing ethylene glycol and terephthalic acid. It is used to make textile fibers, disposable beverage bottles, aat:300380208 polyethylene terephthalate photographic film, and magnetic recording tape. Polyethylene terephthalate (PET) was the first commercially marketed polyester, sold as Dacron (TM) in the U.S. A synthetic wax made by catalytic polymerization of low molecular weight, high-density ethylene. It may be used as a reversible protective coating in many applications aat:300379511 polyethylene wax including the conservation of outdoor sculpture. A superpolymer that maintains mechanical and chemical integrity above 400 degrees Fahrenheit for extended periods and has high strength and modulus of elasticity aat:300014553 polyimide and excellent resistance to solvent, oil, and corrosive environment. aat:300014397 polyisoprene Isoprene polymer which includes the main constituent in natural rubber. Thermoplastic polyester manufactured from corn starch or other renewable resources. First developed for use as a synthetic fiber during World War 2 when organic aat:300389999 polylactic acid materials were in short supply. In conservation used as a protective covering for stone materials exposed outdoors. aat:300010417 polymer-impregnated cement Mixture of water, hydraulic cement, aggregate, and a monomer or polymer; polymerized in place when a monomer is used. aat:300010749 polymer-impregnated concrete Concrete in which an organic polymer serves as the binder. aat:300379458 polymethyl methacrylate (polyacrylate) Polymerized methyl methacrylate, a thermoplastic resin widely used as a glass substitute (e.g., Plexiglass (TM)) and a bonelike material for prosthetics. Tough, lightweight, rigid plastic made by the polymerization of high-purity propylene gas in the presence of an organometallic catalyst at relatively low pressure and aat:300014489 polypropylene temperature. aat:300014492 polystyrene A clear plastic or stiff foam, a polymer of styrene, used chiefly as an insulator in refrigerators, air conditioners, and for packaging. Synthetic rubber formed from a salt or other compound which contains two or more sulfur atoms bonded together as an anion or group that are capable of recovering aat:300014404 polysulfide elastomer their original shape after being stretched to great extents. aat:300014495 polyurethane Plastic based on polyether or polyester resin. Versatile plastic foam used as casting, mounting, packing, and transfer material in applications such as upholstery, thermal insulation, and garments, and in objects aat:300380436 polyurethane foam conservation. Any of a group of thermoplastic resins made by condensing polyvinyl alcohol with an aldehyde and used chiefly in the form of sheets and films, molded products, aat:300014506 polyvinyl acetal coatings, adhesives; especially, the resin made from acetaldehyde. aat:300014507 polyvinyl acetate Synthetic resin derived from the polymerization of vinyl acetate. Used primarily as the filming agent in water-based paints, and also as an ingredient in adhesives. A thermoplastic resin that is soluble or swells in water and can become insoluble in time through crosslinking; used chiefly for emulsifier, adhesive, and film resistant to aat:300014509 polyvinyl alcohol solvent and abrasion, and in making molded and extruded products, and polyvinyl acetal. A tough, flexible, transparent, moistureproof polyvinyl acetal resin made from polyvinyl alcohol and butyraldehyde; used, among other things, as the interlayer in safety aat:300014511 polyvinyl butyral glass and other laminated products. aat:300014513 polyvinyl chloride A thermoplastic resin derived by the polymerization of vinyl chloride, used for thin coatings, insulation, and pipes. A colorless, flexible thermoplastic resin produced by the condensation of polyvinyl alcohol with formaldehyde that is used as a structural adhesive. In conservation, aat:300387259 polyvinyl formal plasticized polyvinyl formal film has been used to fill losses in ancient textiles. aat:300387260 polyvinyl siloxane A hydrophilic silicone elastomer introduced in the 1970s. It is used in dentistry for dental and gingival impressions. Synthetic resin that is produced by the polymerization of vinylidene chloride. Discovered in 1933, and developed as a flexible film primarily used as a food wrap, initially aat:300014551 polyvinylidene chloride marketed as "Saran Wrap." It is used as a barrier against water, oxygen and vapor. Chemically resistant to alkalies and acids, it is insoluble in oil and organic solvents, and is impervious to mold, bacteria, and insects. Oil obtained from the seeds of the opium poppy, Papaver somniferum. When cold pressed, it is a naturally, colorless, transparent oil used as a drying oil, sometimes used aat:300014299 poppy-seed oil as an additive to linseed-oil colors. Hot pressed oil is reddish. It produces a soft, rubbery paint film with a long wet-in-wet work time that was popular with Impressionist painters. Thick layers of poppy oil paint films tend to wrinkle and crack on aging. A material comprising white clay, or "kaolin," and a feldspathic rock, that react when fired so the clay serves to hold the shape of the object and the rock fuses into a aat:300010662 porcelain (material) natural glass. In China, it includes any such ware that is highly fired enough to produce a ringing sound when struck. In Europe, it is limited to hard-fired ceramic that is translucent. A bright white and sparkling marble, sometimes with orange stains, that is quarried near Olympia in the Peloponnesus in Greece. Similar to Parian marble but with more aat:300011604 porino compact texture and smaller grain, it is the only white marble that does not effervesce upon contact with nitric acid. Variously defined limestones, occurring in Egypt and the Peloponnesus and extensively used as building materials by the ancient Greeks; apparently included several aat:300011374 poros materials, such as tufa, travertine, fossiliferous limestone, and onyx marble. A dark purplish-red rock, first quarried in ancient Egypt, containing relatively large crystals in a fine-grained igneous matrix. One of the hardest rocks, it takes a high aat:300011232 porphyry polish and is valued as a durable sculptor's material and as a decorative architectural material. It is considered the best material for the muller and slab used for grinding artists' colors. binding material in the form of a finely ground powder, usually gray, that is manufactured by burning and grinding a mixture of limestone and clay or limestone and shale. The cementitious binder for most structural concrete; obtained by pulverizing clinker consisting essentially of hydraulic calcium silicates; contains calcium sulfate aat:300010377 portland cement as an interground addition. When mixed with water, the anhydrous calcium silicates and other constituents in the portland cement react chemically with the water, combining with it (hydration) and decomposing in it (hydrolysis) and hardening and developing strength. Joseph Aspdin, of England, patented the basic process in 1824, naming it for the resemblance of the cement when set to portland stone, a limestone from the Isle of Portland. aat:300010386 portland slag cement A type of cement composed of an even mixture of portland cement and fine granulated blast-furnace slag. aat:300010388 portland-pozzolan cement Portland cement blended with pozzolana. aat:300380316 portlandite A calcium hydroxide mineral, a member of the brucite group, that is a product of the hydration of portland cement. A marble from Portovenere and the island of Palmaria in Liguria, Italy. The best grades are dark black with evenly distributed dull golden veins while the inferior grades aat:300011539 portor marble are brownish gray with irregular veins and spots of dull yellow. aat:300386527 posnjakite A copper sulfate hydrate mineral used historically as a green pigment. Refers to a type of glass characterized by being one deep color throughout its thickness. The process by which it is made is ancient, and requires the combination of silica, potash, and lime, with metal oxides added to the molten glass for color. The name refers to the metal oxides and the custom of melting the compound in a clay aat:300263714 pot-metal glass pot in the furnace. This type of glass was generally used in making stained-glass windows, with the typical effect of relatively little light penetrating the deep, saturated colors of the glass. A technique was later developed to create "flashed glass," which layers color over clear or white glass and allows more light to pass through the window. aat:300183873 potash A potassium carbonate in the form of a white alkaline granular powder. It is used in glass manufacture, soft soap, and wool washing. A naturally occurring metallic element with symbol K and atomic number 19. Potassium is a soft, silvery-white metal that rapidly oxidizes in moist air. It does not occur aat:300212821 potassium in nature in the free state because it is highly reactive. It is found mainly as potassium chloride (sylvite) and in clays (orthoclase, microcline). Major potassium salt deposits include the Great Salt Lake and Salduro Marsh in Utah and the Dead Sea between Israel and Jordan. Potassium salts are used to make fertilizer and hardened aat:300213350 potassium chloride A white or colorless crystalline solid or powder of the composition KCl, used for molten salt baths, for the heat treatment of steels, for fertilizers, and in explosives. aat:300213125 potassium citrate Colorless or white deliquescent crystals or powder that is soluble in water and glycerol and almost insoluble in alcohol. It is odorless but has a cooling saline taste. aat:300212820 potassium compounds Substances composed by the chemical union of potassium with additional elements. A caustic deliquescent solid of the composition KOH, used as a bleach and in the production of liquid soaps and detergents, oxalic acid, matches, and many potassium aat:300011725 potassium hydroxide compounds. aat:300213123 potassium hypophosphite White, highly deliquescent opaque crystals or powder that is soluble in water and alcohol and decomposed by heat. It has a low toxicity and a pungent saline taste. A potassium salt of lactic acid used to treat leather to counteract acid present in the leather from manufacturing processes or from air pollution; it is also used to aat:300213127 potassium lactate safeguard against future incursion of acid or acid-forming material. Some controversy exists over the possible discoloration potassium lactate may cause to leather as well as its overall effectiveness as a leather/acid buffer. A gray, crystalline mass that forms potassium hydroxide; it is soluble in water, alcohol, and ether. Toxic and corrosive to tissue, it used as a chemical reagent and aat:300213121 potassium oxide intermediate. aat:300213119 potassium permanganate A dark purple crystalline compound of composition KMnO4, used in deodorizers and dyes and as an oxidizing agent and disinfectant. aat:300255860 potassium peroxide White to yellow mass of amorphous crystals, with the chemical structure K2O2; used as an oxidizing and bleaching agent. White crystalline compound that is soluble in water and insoluble in alcohol. Its uses include: reducing agent in photography, oxidizing agent, antiseptic, soap aat:300213117 potassium persulfate manufacture, and desizing of textiles. A glass-forming soluble silicate salt with many applications. In conservation, potassium silicate in solution has been applied, for example, as a consolidant for fragile aat:300379793 potassium silicate stone and earthen structures and as a binder for the pictorial reintegration of outdoor mural paintings. Colorless double salt first prepared in La Rochelle, France, and thus also known as Rochelle salt. It is used as an analytical reagent, as a laxative, and in making aat:300390605 potassium sodium tartrate mirrors.In conservation science, it is used in saturated solution as a cleaning agent on bronze and other metal objects. aat:300011667 potstone A soft, easily carved soapstone, used since prehistoric times for making pots and other household utensils. aat:300010453 potter's clay Native clay selected for its fineness, plasticity, absorbency, and other qualities that suit it to various ceramic uses. General term for greenstone found on South Island, New Zealand. The term refers to any of three different types of stone: nephrite, bowenite, and serpentinite. Maori aat:300379291 pounamu do not classify pounamu by geological origin, but by appearance according to color, markings, and translucency. There are many local names for different pounamu, but four main varieties are widely recognized: inanga, kahurangi, kawakawa, and tangiwai. aat:300162658 pozzolan cement Cement made with lime mortar and pozzolana or other material containing active silica. A rosy red volcanic clay that has been used as a pigment and a component in cement; pozzolana itself possesses little or no cementitious value, but in finely divided aat:300014780 pozzolana (clay) form and in the presence of moisture, it will chemically react with calcium hydroxide at ordinary temperatures to form compounds possessing cementitious properties. Pozzolana is mined at Pozzuoli near Naples, Italy. It has been used since ancient times by the Romans. aat:300311434 prasine (mineral or pigment) General term referring to various green stones or minerals, particularly those used as gem stones, such as emerald, or those used as pigment, such as green earth. aat:300011054 precious metal Metal considered to have high intrinsic value, such as gold, silver, and platinum; traditionally used to make such objects as jewelry and coins. aat:300133732 precious stone (material) Gemstone that is considered more valuable than other types, especially diamond, sapphire, emerald, ruby, and sometimes pearl. Pure, artificial calcium carbonate; frequently a by-product of drug and chemical manufacturing. Used industrially as an inert pigment, as well as in gesso grounds and aat:300011731 precipitated chalk pastel crayons. aat:300010650 pressed brick A stiff mud brick made under high pressure; it is homogeneous, and has increased density and strength. aat:300210941 pressed glass Glassware produced when hot molten glass is poured into a mold and made to conform to it by means of a plunger; the interior form is independent of the exterior form. aat:300013010 propane Liquefied petroleum gas, marketed under pressure in steel cylinders as bottled gas; used especially in cook stoves. Any of a large class of natural polymers composed of chains of amino acids connected by peptide linkages. Proteins occur in the cells of all living organisms and in aat:300206575 protein biological fluids. Their primary structure is determined by the order of their amino acids. Examples of soluble proteins include enzymes and antibodies. Insoluble proteins include keratin and collagen. Examples of protein containing compounds are leather, gelatin, albumen, animal glue, silk, ivory, egg, and casein. A rare brown or black mineral resembling brookite occurring in volcanic rocks as tabular crystals. It has been identified as an element in the yellow slip of Gallo-Roman aat:300387258 pseudobrookite marbled ware excavated in Graufensenque, France. aat:300013823 pumice (pigment) Finely ground pigment made from pumice vocanic stone, used to make a clear glaze for ceramics. A pale gray, porous variety of the volcanic stone rhyolite; it is composed of potassium aluminum silicate with small amounts of iron and alkalis. Pumice is used as an aat:300011250 pumice (volcanic rock) abrasive for polishing jewelry, cleaning metals, and smoothing vellum and parchment. In its solid form it is used as an abrasive and aggregate and in its powdered form it is used as a polish and abrasive. aat:300386701 pumpkin seed oil Vegetable oil with many culinary uses; also used traditionally as a binder for body paint by Native Americans of Baja California. A particular type of processed beeswax that was used in encaustic paintings. Punic wax was probably made by combining beeswax with soda lime to produce a waxy aat:300014591 punic wax soap. Repeated washings in hot water removed any excess caustic. Experiments conducted in Berlin to recreate an ancient recipe yielded flakes of a hard brittle wax that melted between 73-75C (163-167 F). aat:300011661 purple slate Slate that has components of hematite and chlorite, causing a purplish color. A common yellowish isometric mineral made of iron disulfide. It is reflective and its sparkling nuggets have been mistaken for gold. Pyrite may be incorporated into fossil aat:300011112 pyrite deposits. Under conditions of high humidity the mineral may oxidize and form iron sulfate. This oxidation product expands and causes fossil specimens to fracture and crumble in a condition known as "pyrite disease," or "pyrite decay." A natural, solid, hydrocarbon substance, distinguishable from bitumen by being infusible and insoluble. When heated, however, pyrobitumens generate or transform into aat:300212377 pyrobitumen bitumen-like liquid or gaseous petroleum compounds. This class of natural bituminous material includes peat, lignite, and coal. Rock formed when dislocated and rupturing solid material is explosively or aerially ejected from a volcanic vent or rock formed when solid fragments are incorporated aat:300011253 pyroclastic rock into moving lava. aat:300266184 pyrolusite An ore of manganese that is dark grey in color; manganese dioxide. Used to decolorize glass. A major class of silicate minerals and its members which include about twenty mineral species, among them diopside, rhodonite, jadeite. Pyroxenes are found in many aat:300386789 pyroxene igneous and metamorphic rocks. They are distinguished from the second major class of silicate minerals, amphiboles, by their cleavage planes, characterized by prismatic cleavage at nearly 90 degrees, and a structure of single chains of SiO4 tetrahedra as distinct from amphiboles' double chains. aat:300014448 pyroxylin A flammable mixture of cellulose nitrates usually with less than 12.5% nitrogen. Refers to a type of pâte de verre that is characterized by being especially translucent. It was developed by Gabriel Argy-Rousseau, a famous Art-Deco glass designer of aat:300263724 pâte de cristalle the 1920s and 1930s. Refers to glass created by a technique in which ground glass is made into a paste and molded into a vessel or figure, and then the design is refined by carving. Glass aat:300263723 pâte de verre (glass) created by this method was known in ancient times and revived in France in the late 19th and early 20th centuries, notably in the studio of glass and jewelry designer, René Lalique. aat:300010684 quarry tile Unglazed ceramic tile, machine-made by the extrusion process from natural clay or shales. aat:300010477 quarter closer A brick which has been cut to one-fourth of its normal length but is of normal thickness and width; used to space normal-sized brick. aat:300011132 quartz (mineral) The most common variety of silica; commonly occurs as crystals. A transparent variety of the silica mineral quartz that is valued for its clarity and total lack of color or flaws. Vessels and spheres have been carved from large crystals since ancient times, and the application of the word "crystal" to fine glassware derives from this practice. Quartz crystal formerly was used extensively as a gemstone, aat:300011152 quartz crystal usually brilliant-cut, although it has now been largely replaced by glass; rhinestones originally were quartz pebbles found in the Rhine River. The optical properties of quartz crystal led to its use in lenses and prisms; its piezoelectric properties are used to control the oscillation of electrical circuits. Its physical properties are those of quartz. aat:300011219 quartz diorite Diorite containing appreciable amounts of quartz. aat:300011238 quartz porphyry A porphyritic rhyolite containing phenocrysts of quartz and alkali feldspar in a microcrystalline or cryptocrystalline groundmass. A metamorphic rock composed largely of granular quartz which is cemented by silica forming a homogeneous mass of very high tensile and crushing strengths; aat:300011623 quartzite especially used as a building stone, as gravel in road construction, and as aggregate in concrete. aat:300010479 queen closer A brick which has been cut in half along its length; it is of normal thickness but one-half normal width; used to complete a course or to space normal-sized brick. aat:300010985 queen's metal A britannia metal with a small amount of zinc. Lime prepared by calcining limestone in a kiln at about 500 C to form a white amorphous powder that may contain small amounts of silica, iron, magnesium, and/or aat:300011740 quicklime aluminum oxides. Oyster shells have been used to make a very pure quicklime. Once water is added, quicklime becomes slaked lime. Semi-liquid, loose sand which can suck down heavy objects that rest on its surface. Artist Robert Smithson featured the use of quicksand in his work The Hypothetical aat:300312094 quicksand Continent in Stone: Cathaysia (1969). aat:300266365 rabbitskin glue Hide glue made from rabbits. Used as a primer for canvases. Hard, fine-grained siliceous sedimentary rock composed of the remains of radiolarians, single-celled organisms that sink to the seafloor and form this rock, or radiolarian aat:300400620 radiolarite earth. Radioactive chemical element having symbol Rn and atomic number 86. It is a colorless, odorless, tasteless inert gas. Radon is formed during the natural decay of aat:300380555 radon radium. It is produced in rock and soil and migrates to the surface, sometimes entering buildings through basement walls, resulting in low level exposure. Radon’s health risk is associated with the products of radon decay and not with the gas itself. A hard, coarse, rubbly or shelly sedimentary rock that weathers with a rough irregular surface, such as a flaggy sandstone or limestone; used primarily as a building aat:300011359 rag (stone) stone. aat:300014365 rammed earth A material usually consisting of clay, sand, or other aggregate, such as sea shell, and water, which has been compressed and dried; used in building construction. aat:300011208 rapakivi A coarse red granite quarried in Finland, characterized by unusual ovoid ringed feldspars; often used for building in northern Russia. aat:300014326 rape oil An oil obtained from seeds of the mustard family. aat:300012989 rapid-curing asphalt Cutback asphalt composed of asphalt cement and a naptha or gasoline-type diluent of high volatility, which evaporated rapidly. aat:300386743 raspite A rare secondary mineral occurring as brownish, yellow or gray prismatic crystals in the oxidized zones of tungsten-bearing hydrothermal base metal deposits. aat:300014276 raw oil A commercial grade of linseed oil that is the slowest-drying. aat:300010774 ready-mixed concrete Concrete for delivery to a site in an unhardened state for immediate use. aat:300220060 reagent grade water Water of the highest purity that is available from a practical standpoint. An orange-red mineral, found as soft lumps consisting of arsenic disulfide, having a resinous luster; it is found in eastern Europe, Asia, and western North America in aat:300013561 realgar (pigment) lead and silver ores along with orpiment (arsenic trisulfide). Realgar was once widely used as a pigment because of its bright rich color in works from China, India, Central Asia, Egypt, and Europe. However, it is extremely toxic, not stable, and can deteriorate badly in oil paint films. Refers to a type of glass that is characterized by an irregular rippled effect in the color, caused by a mixture of glass of different hardnesses. It is usually a blend of white aat:300263717 reamy glass with colored glass, the word "reamy" referring to the creamy white color. It may be similar in appearance to "cloudy glass" and "streaky glass." It is often used to make windows. A rock, similar to diorite, composed of a compact felsitic base in which hornblende or feldspar is porphyritically developed. The celebrated red Egyptian porphyry or aat:300011240 red antique porphyry 'Rosso Antico' is a red antique porphyry. aat:300013550 red bole Reddish pigment made of a fine, soft, natural red clay. aat:300133706 red brass Brass having a reddish tint due to a high copper content. Drawing medium made from natural red clay containing iron ocher, ranging in color from reddish brown to blood red. It was used for wall paintings by ancient Egyptians aat:300080064 red chalk and Romans; in the 16th century it was a popular drawing medium. Originally cut from deposits but later fabricated from the same material. aat:300011205 red granite Granite with a mineral composition that results in a red color and usually a relatively coarse texture. aat:300410508 red lacquer Lacquer mixed with powdered cinnabar, applied in thick coats, often carved to produce the traditional red lacquerware in China. Heavy, opaque, orange-red pigment composed of lead tetroxide. Although chemically equivalent to the mineral minium, red lead pigment has been synthetically prepared by roasting lead white (480 C) since before the 5th century BCE. Red lead has been found as a pigment on early objects from Egypt, China, Japan, India, aat:300013647 red lead (pigment) Persia, and Rome; it is no longer used as an artist's color because is has poor light stability and poor working properties, although it is still used to color glass and ceramic glazes. Pliny called it "secondarium minium." It was widley used in illuminated manuscripts, and with its use, the term "miniare" came to mean "to color with red lead," giving rise to the term "miniature." Red lead paint was used as an anticorrosion primer for structural iron and steel until the late 20th century. aat:300011523 red marble Marble with a mineral composition resulting in a predominantly red color. aat:300011660 red slate Slate that has a component of hematite, causing a reddish color. aat:300263721 reeded glass Refers to a type of sheet glass characterized by a linear relief paatern or texture that is created by using a ridged roller in the manufacturing process. aat:300010881 reflective glass Window glass coated on the outside with a transparent metallic coating that reflects light and radiant heat. aat:300010775 reinforced concrete Concrete that contains embedded reinforcements, typically steel bars, in order to increase strength. Any composite plastic imbedded with high-strength fillers, resulting in mechanical properties superior to base resins. Reinforcement may be derived from fibers, aat:300014583 reinforced plastic filaments, mats, fabrics made of glass, metal, carbon, boron, or aluminum silicate. The types of plastics used for base resins include polyester, epoxy, phenolic, polypropylene, polystyrene, nylon, polycarbonate, and polyphenylene oxide. General term for solid or semisolid organic substance usually obtained from plant secretions, but sometimes obtained from insects or synthetically produced. It is soluble aat:300012882 resin (organic material) in organic solvent but not in water, and is commonly used in varnish, printing ink, and size. It is distinguished from "gum" by not being dissoluble in water. To distinguish between natural and synthetic resins, use the narrower terms "natural resin" or "synthetic resin." General term for any of a large group of fossil resins occurring in deposits of brown lignite, peat, etc. These resins resemble succinite in appearance, but contain little or aat:300311356 retinite (fossil resin) no succinic acid. Around 40 varieties of amber are recognized, divided into two main groups: those containing succinic acid make up the succinite group and those having little or no succinic acid belong to the retinite group. A colorless artificial gem of paste or glass, often with facets that sparkle in imitation of a diamond. Also refers to foil-backed or silvered cut glass used to imitate aat:300010806 rhinestone diamonds. Rhinestones were originally quartz pebbles found in the Rhine River, thus the name. Mineral composed of manganese carbonate (MnCO3), appearing transparent to opaque pink to deep red in color; used as an ornamental stone and source for aat:300312061 rhodochrosite manganese. Found in hydrothermal veins along with other manganese minerals in low temperature ore deposits as in the silver mines of Romania, Germany, and Britain; also found in South and North America. aat:300380137 rhodolite A pink to light violet variety of garnet; is used as a gemstone. aat:300387077 rhodonite Manganese silicate occurring as rose-pink or brownish crystals sometimes used as a gemstone. Any of a number of extrusive acid igneous rocks, usually porphyritic and exhibiting flow lines, with phenocrysts of quartz and alkali feldspar in a glassy to aat:300011211 rhyolite cryptocrystalline groundmass; the extrusive equivalent of granite. aat:300014328 rice oil Vegetable oil obtained from rice bran and used in cooking. aat:300010715 ridge tile A tile which is curved in section, used to cover the ridge of a roof. aat:300011692 rock (inorganic material) Naturally formed aggregate of one or more minerals. For processed or dressed rock use "stone." Porous rock such as sandstone or limestone that has become impregnated with natural asphalt through a geological process, so that the asphalt has more than 10% aat:300012981 rock asphalt minerals. Sodium chloride that occurs naturally as, or obtained mechanically from, a mineral deposit and sold as large crystals. Rock salt is used to melt ice, as a food aat:300386505 rock salt preservative, and for the production of soda ash by the glass industry. To refer to the mineral composed of sodium chloride, use "halite." aat:300010851 rolled glass A flat glass of considerable thickness made by passing a roller over molten glass. aat:300011707 roofing granules Crushed rock, slate, slag, porcelain, or tile, crushed into particles and graded, used as surfacing on asphalt roofing and shingles. aat:300014348 roofing sand A fine white silica sand. aat:300011650 roofing slate A thin, usually rectangular, piece of certain varieties of slate or other stones which split readily into sheets and are used to cover the roofs of buildings. aat:300010699 roofing tile A tile for roofing usually of burnt clay, concrete, or asbestos cement; available in many configurations and types such as plain tiles, single-lap tiles, and interlocking tiles. aat:300010967 rose gold Gold with a ruddy mat surface finish. aat:300380422 rose granite Granite quarried at Aswan, Egypt with a mineral composition that results in a rose color. It is the type of granite most used in Egyptian architecture. aat:300011155 rose quartz A pink variety of quartz used as a gemstone. A pungent essential oil obtained from the flowering tops of rosemary and used chiefly in soap, cologne, hair lotion, pharmaceutical preparations, and as a retardant in oil aat:300014266 rosemary oil paint. aat:300404831 rosewater Water distilled from roses or scented with essence of roses, used as a perfume, scenting a room, flavoring, in medicinal preparations, or for other purposes. The solid, brittle, clear resinous residue left after the distillation of turpentine from balsam, having a color ranging from yellow or reddish-brown. It becomes sticky when warm and has a faint pine-like odor. Primarily composed of abietic acid (about 80%), rosin reacts in hot alkaline solutions to form rosin soaps. Rosin weathers poorly, aat:300012950 rosin becoming oxidized and brittle with age. It also has poor moisture resistance. Although many of its aging properties are undesirable, rosin is or was used as an ingredient in paints, varnishes, inks, adhesives, sealing wax, soldering fluxes, sizing paper, and linoleum. Because it increases sliding friction, it is commonly used for coating bows of some stringed instruments, and as a slip preventative on the floors of stages and shoes of dancers. The inexpensive resin is also used for sizing paper. aat:300387666 rosso ammonitico Veronese A red, nodular limestone; a Jurassic sedimentary that crops out in the Trento Plateau in the Southern Alps. It is a common building stone in Northern Italy. aat:300011462 rosso brecciato A breccia marble from Lydia in present-day Turkey; its color ranges from bright or brownish red to various hues of purple and it typically contains white pebbles or spots. aat:300311576 rosso di Levanto A serpentinite from the Italian Riviera having a red color. aat:300011570 rosso di francia A red marble with large irregular stains of flinty blue that originates from the southeast of France. aat:300011363 rottenstone A soft, friable, earthy stone of light gray to olive color, used as an abrasive for metal and wood finishing. aat:300011531 rouge antique marble A red marble often used in antiquity; it is found in Cynopolis and Damarestica in Greece. Reddish-brown to cherry red limestone with gray, blue and red streaks and veins or spots, derived primarily from the province of Hainaut, and used extensively as aat:300011528 rouge de Rance material for furniture and architecture in Paris in the 16th-18th centuries, and notably at Versailles. aat:300386448 rozenite A secondary sulfate mineral found in mine waste. A natural hydrocarbon polymer formed from the resinous latex of trees of the Hevea and Parthenium genera. To prepare natural rubber, the latex is collected from a cut in the bark, precipitated with acid, then washed and dried. Rubber is very elastic and was used for bowls, shoe soles, adhesives, and bouncy balls. However, when cooled, rubber becomes brittle and when warmed it becomes sweaty and tacky. Prior to the development of synthetic resins, unvulcanized rubber was used for adhesive tapes and crepe shoe soles. In 1839, Charles Goodyear discovered that rubber can be hardened with the vulcanization process in which sulfur is used to initiate aat:300012941 rubber (material) crosslinking of the hydrocarbon strands. Higher sulfur content produces a harder, denser material. Vulcanized rubber is used to make rubber bands, foams, fabric coatings, small objects, combs, pens, and musical instruments. Vulcanized rubber, however, will emit sulfur when exposed to light or heat causing the rubber to degrade and become brittle. Since the 19th century, small amounts of wax have been added to the rubber during vulcanization. The wax slowly migrates to the surface and provides a thin layer of protection from oxidation. aat:300011693 rubble Rough, broken stones or bricks. For use in masonry, use "rubblework." aat:300010753 rubble concrete Form of concrete reinforced by broken stones or brick. Pure metallic element having symbol Rb and atomic number 37; soft, silvery white, and very reactive, rubidium is found as a trace constituent of various alkali minerals. aat:300380179 rubidium It is used in photoelectric cells and as a catalyst. aat:300011082 ruby (mineral) A red variety of the mineral corundum that ranks with the best grades of precious stones as a gemstone; off-color rubies are used for watch and instrument bearings. aat:300206372 ruby glass Glass with a ruby color due to the presence of various materials, including colloidal gold, cadmium selenide, or copper and zinc sulfide. aat:300011423 rudaceous rock Sedimentary rock composed of a significant amount of rounded or angular fragments coarser than sand grains. aat:300011365 ruin marble A brecciated limestone that, when cut and polished, gives a mosaic affect suggesting the appearance of ruins or ruined buildings. Fossil resin found in Romania. Similar to succinite, but it has been held to be of different botanical origin. Recent studies suggest that differences instead indicate that aat:300311357 rumanite (amber) ruminite is a succinite that has suffered partial thermal degradation during the folding of the Oligocene Kliwa sandstone formation in which it is found. aat:300010549 rustic brick A fired-clay brick that is typically used for facing work and is rough-textured and often multicolored. aat:300010533 saddle-back coping brick A coping brick with a sloped top surface; its high point is along the center ridge so that rainwater spills on either side. A material composed of two sheets of plate glass with a sheet of transparent resinoid between, the whole molded together under heat and pressure. It will crack without aat:300010884 safety glass shaatering when subjected to a severe blow. aat:300014301 safflower oil A pale, non-yellowing drying oil of good film-forming properties and excellent color retention. aat:300380557 salep A starchy powder made from the root of several species of the Orchis genus containing a nutritive starch. aat:300183627 salt (inorganic material) Any substance resulting from the combination of negative ions from acids and usually metal ions. For common table salt, or NaCl, use "sodium chloride." aat:300162511 salt water Water that contains a large amount of salt. aat:300010618 sammel brick Under-fired brick with a rough texture and pink hue. An uncommon copper phosphate mineral found in the oxidized zones of copper deposits in Chile and as a rare mineral in caves. It is also found as a corrosion product on aat:300386449 sampleite ancient copper alloy objects from Memphis, Egypt. Material consisting of fragmented particles of mostly siliceous rock, specifically as it appears on the surface of a beach or a desert. Individual particles may range in aat:300014341 sand diameter from approximately 0.0008-0.08 inch. Most rock-forming minerals at the Earth's surface may be constituents of sand, but a limited number are common. Quartz is most common. Brick, usually pearl-gray in color, made of a sand and lime mixture, molded under pressure and cured with steam. It possesses good frost, acid, and fire resistance and aat:300010434 sand-lime brick is easily washed. aat:300010636 sand-struck brick Brick formed in a mold that has been sprinkled with sand to facilitate removal. A pale yellow natural resin from the Callitris genus that is native to Australia and from the species Tetraclinis articulata that native to northern Africa. Although sometimes called "gum juniper," sandarac is not derived from true junipers of genus Juniperus (see "juniper resin"). Drops of resin, "sandarac tears," are hard and brittle aat:300012954 sandarac (resin) with a white powdery surface due to oxidation, the substance forms a clear, hard film that becomes darker and redder with age. Sandarac spirit varnishes dry quickly and have been used for retouching, making protective and decorative coatings, and as an artists' paint vehicle. A consolidated sedimentary rock, consisting of sand grains united with a natural cementing material; the most common sand in sandstone contains quartz, with aat:300011376 sandstone considerable feldspar, lime, mica, and clayey maater. Distinctive pressed glass of various colors produced by the Boston Sandwich Glass Company. For double-wall glass objects with inner decoration of engraved gold leaf, aat:300207375 sandwich glass use "gold glass (visual works)," having the UF "sandwich gold glass (visual works)." aat:300210991 sanidine Glassy form of orthoclase in which sodium may replace up to half of the potassium. aat:300011269 santorin A lightweight, gray, volcanic tuff, used as pozzolana. aat:300387628 sanukite Variety of andesite produced by now-extinct volcanoes in the Inland Sea area of Japan. It was used during the Paleolithic and Postglacial periods for stone implements. aat:300014277 saponified oil Oil converted into a soap or crystalline form through combination with an alkali. Any of a group of glycosides obtained from plants that gives a soapy lather with water. Saponin is obtained from several unrelated species, including the bark of the soap aat:300012958 saponin bark tree, the roots of the soap plant, the fruit of the soapberry tree, and the leaves of the soapwort plant. Saponins have been used since ancient times as a natural cleaner. Uses include in solution as a mild detergent for cleaning dirt and smoke from paintings. It is poisonous to fish or if injected into the bloodstream. aat:300011083 sapphire (mineral) Any pure gem variety of corundum other than ruby. A nitrogen-rich, combustible, sludge-like black sedimentary deposit that occurs as a result of the decomposition of microorganisms in anaerobic conditions on the aat:300380558 sapropel bottoms of lakes and seas. Compressed into hard rock, sapropel becomes oil shale or sapropelic coal. aat:300012878 sarcocolla Gum from some species of Astragalus or Penaea, mentioned in ancient writings and also in English 18th- and early 19th-century painting recipes. aat:300209773 sard A deep orange red variety of chalcedony, similar to but darker than carnelian; used as a gemstone. aat:300011137 sardonyx A gem variety of chalcedony with parallel layers of sard and a mineral of another color. A large, loose residual mass of stone left after the erosion of a once continuous bed or layer; often used to specifically refer to one of the large sandstone blocks aat:300011672 sarsen scaatered over the English chalk downs. Oil extracted from the root bark sassafras trees, native to North America and Asia. Sassafras oil is used as an odorant in fabrics, a flavorant, and an ingredient in soaps aat:300375358 sassafras oil and medicine. aat:300207378 satin glass Glassware decorated with a maate finish. aat:300167875 scallop shell Shell of a scallop. Rare-earth metallic element having symbol Sc and atomic number 21. Scandium is a soft, silvery-white metal which does not tarnish in air. It was discovered in 1879 but aat:300386739 scandium predicted a decade earlier and given its initial name, ekaboron. Stock comprising pieces of material that are small or otherwise of non-standard dimensions. As applied to timber, usually denotes the sectional dimensions (thickness aat:300012831 scantling and breadth) in contradistinction to the length, of a square-edged piece of nonstandard dimensions. For a block of stone, a piece measured in all three dimensions. aat:300380560 scapolite One of a group of rock forming minerals composed of silicates of calcium, sodium and aluminum. Marialite, meionite, ekbergite are members of the scapolite group. aat:300013580 scarlet vermilion (pigment) The bluish, or least yellowish, variety of vermilion. aat:300011626 schist A rock, the constituent minerals of which have assumed a position in more or less closely parallel layers due to metamorphic action. aat:300011053 scrap metal Discarded metal, often fragmented, that is suitable for reprocessing. Form of sodium chloride, with small amounts of magnesium chloride, magnesium sulfate, and calcium sulfate, that is obtained from the evaporation of salt water; often aat:300386508 sea salt comprising larger crystals than table salt. Resinous preparation of shellac and turpentine, or of beeswax and Venice turpentine with coloring maater, that is plastic when warm and used for sealing letters, aat:300311202 sealing wax aataching impressions of seals to documents, and sealing baateries and jars. Eroded maater from preexisting rocks which is carried and deposited by water, wind, or ice, forming layers on the Earth's surface and fluvial deposits. Sedimentary aat:300379424 sediment rock.is composed of consolidated sediment. aat:300011273 sedimentary rock Rock, such as sandstone or limestone, formed from materials deposited as sediments. aat:300133707 selenite A variety of gypsum occurring in transparent crystals or crystalline masses. aat:300156319 selenium Nonmetallic element with symbol Se and atomic number 34, obtained chiefly as a by-product in copper refining. aat:300380308 self-consolidating concrete Concrete mix that can be placed purely by means of its own weight, with little or no vibration. A material of white to light gray or light yellow color, extremely lightweight, absorbent, and compact, that is found in Asia Minor and is used for making tobacco pipes aat:300209722 sepiolite and ornamental carvings. A large, generally spheroidal concretion, usually made of impure limestone or clay ironstone, having polyhedral blocks that are internally cemented together by aat:300011422 septarium crystalline minerals. Gelatinous protein that cements silk fibers together in the cocoon. Sericin is secreted along with fibroin by the insect. It is usually removed, by boiling the raw silk in aat:300380563 sericin soap and water, during fabric manufacture. A serpentinite whose predominant color is usually a shade of green although there are a few purple varieties. It often bears a strong resemblance to granite; the best aat:300011634 serpentina comune serpentina comune comes from Liguria, Italy. An ornamental mineral composed of hydrated magnesium silicate, having a greasy or silky luster, a slightly soapy feel, and a tough, conchoidal fracture. It ranges in aat:300011627 serpentine (mineral) color from yellow, green, gray, brown, or black, with crystals of green olivine and black veins or patches. Serpentine has been gathered or mined since Paleolithic times, used for decorative vessels, jewelry, building stones, and as a source of abestos. Metamorphic rock containing of serpentine (magnesium silicate) and calcite (calcium carbonate) cemented together with red iron oxide (ferrous oxide). Serpentine or ophicarbonate stones have fragments of red, white, and green colors, although the overall hue is typically greenish. The stones polish to a high gloss, which has led to aat:300210275 serpentinite them being occasionally mislabeled as marble; however, they are fragile and unsuited for sculpture. Its color and ability to take a high polish have made serpentinites popular with many civilizations over time for decorative and ornamental work. aat:300255995 sett Small, rectangular block, generally of granite, used for paving streets and walkways. Traditional Japanese alloy of copper and gold. It is often subjected to a chemical process that produces a blue-black patina. Shakudo has historically been used for aat:300380025 shakudo ornamental fittings as on katana. Argillaceous sedimentary rock formed by the compaction of clay, silt, or mud; it may be gray, red, brown, or black. It is finely laminated and weak along planes allowing aat:300011281 shale the rock to split easily. Shape memory alloys are imprinted with a shape so that even after they are deformed, a threshold temperature will bring about a return to the original configuration. aat:300380566 shape memory alloy Copper-aluminium-nickel, and nickel-titanium are the two main types of shape memory alloy. Refers to a type of glass that is made by pressing molten glass through rollers. It is generally characterized by an even texture and uniform thickness. It may also be aat:300010824 sheet glass used more generally to refer to any glass produced in large flat sheets made by blowing, drawing, rolling, or floating. aat:300223016 sheet metal Metal rolled to any given thickness between 0.06 and 0.249 inches and cut into rectangular sections. aat:300011829 shell (animal material) Hard outer covering of invertebrate creatures, composed of calcareous or chitinous material. Gold leaf ground into a powder and mixed with honey or other binder, used to produce powdered effects on leather bindings, to repair or restore gold tooling, and to gild aat:300263579 shell gold manuscripts. Originally packaged in mussel shells, more recently it is sold in plastic containers shaped like mussel shells or in tablet or small block form. aat:300011472 shell marble A dark, gray brown marble, closely packed with fossil shells, which when polished gives a brilliant gleam. The spirit varnish produced from lac, a resinous substance excreted by the female of the lac insect. The lac resin is placed in alcohol to produce a product that creates a aat:300014918 shellac smooth finish and a high polish that is tough but not completely water-repellent. Shellac is a natural thermoplastic. aat:300011300 shelly limestone Fossiliferous limestone composed of shells or shell fragments. aat:300010718 shingle tile A flat clay tile used for roofing. aat:300010657 side-cut brick Brick having the side surfaces wire-cut before firing. aat:300011115 siderite A brownish mineral of the calcite group; common in bed nodules of clay and ironstone, and is an iron ore. aat:300312265 sig water An alkaline solution of soda ash, borax, or ammonia, used as a cleanser and stripper. Sig water was formerly made from a solution of stale urine. aat:300380252 silcrete A very hard crust in or on soil formed of sand grains or pebbles glued together by silica; a quartzite. The dioxide form of silicon, SiO2, occurring in quartz sand, flint, and agate. It is used chiefly in its prepared white powder form in the manufacture of glass, ceramics, aat:300011131 silica (mineral) and abrasives. aat:300014352 silica sand Sand comprised of silica, which is 98% pure, and used in glassmaking. aat:300011354 siliceous limestone Limestone that is rich in silica, particularly as free silica as opposed to silicates. Non-clastic sedimentary rocks with a content of at least 50 percent silicon dioxide, either as quartz or as amorphous silica and cristobalite. Formation is the result of the aat:300400677 siliceous rock accumulation of siliceous organic remains. Included are rocks that have formed as chemical precipitates, but not those of detrital or fragmental origin. The most common siliceous rock is chert. Sandstone that is rich in silica, particularly as free silica as opposed to silicates; the silica characterizes the cement or matrix which binds together the quartz particles of which sandstone is mainly composed. Pure siliceous sandstone is chemically inert, making it able to withstand a smokey environment; it is therefore a popular building aat:300011407 siliceous sandstone stone in industrial areas. It is also hard and durable but difficult to work. Pure siliceous sandstone is white or cream in color; colors are due to impurities: yellow and red colors are due to the presence of iron oxides; green from glauconite; and black from manganese dioxide. Semi-metallic element, having symbol Si and atomic number 14, in amorphous and crystalline forms, occurring in a combined state in minerals and rocks and aat:300011769 silicon constituting more than one fourth of the earth's crust. The chemical industry uses the term "silicon metal" and "silicon" interchangeably, and anything but pure silicon is generally referred to in this context as "semiconductor-grade silicon." aat:300010962 silicon bronze Copper-silicon alloy, either nearly pure copper fluxed with silicon, of which only a trace remains in the final metal, or brass or aluminum bronze containing some silicon. Any solid semi-inorganic polymers based on siloxanes, obtained by the action of concentrated hydrochloric acid on calcium silicide. Silicones were first discovered by F.S. Kipping in England in 1904, but were not commercially produced as polymers until 1943 by Dow Corning and 1946 by General Electric. They were called silicones aat:300014558 silicone because their empirical formula (R2SiO) is similar to that for ketones (R2CO). Silicones can be liquids, gels, and elastomers as well as solid thermoplastic or thermosetting resins. In general, they have excellent heat and chemical resistance and are water repellent. Silicones are used as adhesives, lubricants, protective coatings, release agents, paints, rubbers, coolants, implants, and insulation. aat:300014406 silicone elastomer Semi-inorganic polymers based on siloxanes that will return to approximate original length after stretching, and that demonstrate heat, chemical, and water resistance. A hybrid binder resin used in various applications such as protective coating or primer on corrosion-prone surfaces of metals and concrete, and in other applications aat:300014539 silicone epoxy including high-brightness LED packaging. Rubber made from silicone elastomers and characterized by its retention of flexibility, resilience, and tensile strength over a wide temperature range and its resistance to aat:300133708 silicone rubber weathering and many chemicals. All sediment particles, regardless of mineral origin, that fall within a specified size range between those of sand and clay. An unconsolidated aggregation of particles is aat:300379483 silt also called silt; a consolidated aggregate, silt-stone. aat:300011383 siltstone (mudstone) An indurated silt with the texture and composition of shale but without its fine lamination or fissility; it is a massive mudstone in which silt predominates over clay. Pure metallic element having symbol Ag and atomic number 47; a malleable, ductile, white metal with characteristic sheen, considered a precious metal. Silver is widely distributed throughout the world, occurring rarely as metallic silver (in Peru, Norway) but more often as silver-gold alloys and silver ore. Today silver is obtained as a aat:300011029 silver (metal) byproduct in the refinement of gold, lead, copper, or zinc ores. Silver was smelted from the ore galena as early as 3800 BCE. As a pure metal, silver is second to gold in malleability and ductility, can be polished to a highly reflective surface, and used -- typically in an alloy -- in jewelry, coinage, photography, mirrors, electrical contacts, and tableware. aat:300010975 silver alloy Alloy in which silver is the principle element. aat:300189779 silver amalgam Alloy of silver and mercury. A yellow, water-insoluble powder, AgBr, which darkens upon exposure to light, produced by the reaction of silver nitrate with a bromide. It was used chiefly in the aat:300130944 silver bromide manufacture of photographic emulsions from about 1875-1880. A white, granular, water-insoluble powder, AgCl that darkens upon exposure to light produced by the reaction of silver nitrate with a chloride. It was used chiefly in the aat:300131098 silver chloride manufacture of photographic emulsions and antiseptic silver preparations from about 1895-1900. aat:300127427 silver compounds Compounds created by combining silver with another material. aat:300380110 silver gilding Gold applied over a silver object using the fire-gilding method or by electrolysis. aat:300130942 silver halide A compound in which silver is combined with a halogen, typically silver chloride, bromide or iodide. A pale-yellow, water-insoluble powder, AgI, which darken upon exposure to light, produced by the reaction of silver nitrate with an iodide. It was used chiefly in the aat:300130947 silver iodide manufacture of photographic emulsions from about 1875-1880. Silver beaten out into thin leaf for use in gilding. Silver leaf is about three times as thick as gold leaf because silver is less malleable but the resulting leaf is easier to aat:300265199 silver leaf handle. It requires lacquering or varnishing to prevent tarnishing; for this reason it is often replaced by palladium leaf. In the commerical arts inexpensive aluminum leaf is used to achieve the effect of silver leaf. Silver leaf can also be covered with a golden yellow transparent coating as a substitute for gold. A white, crystalline water-soluble, bitter, corrosive, poisonous powder AgNO3, produced by the reaction of silver and dilute nitric acid. It was chiefly used in the aat:300127428 silver nitrate manufacture of photographic emulsions and mirrors. A dark brown or black powder prepared by combining an aqueous solution of silver nitrate and an alkali hydroxide. It is used in silver-oxide baateries, as a laboratory aat:300380406 silver oxide reagent, and as a carbon dioxide scrubber. Salt-free silver oxide showed promise as a bronze disease treatment used at excavation sites but its application has proven a complex and labor consuming method with aesthetically unappealing results. A yellow powder, Ag3PO4, that turns brown when heated or exposed to light, soluble in acid and very slightly soluble in water. It was used in the manufacture of aat:300131105 silver phosphate photographic emulsions and pharmaceuticals. aat:300379787 silver sulfide A silver ore, also known as argentite, acanthite, and silver glance, used in niello work and as a colorant in ceramic glazes. aat:300045517 silvered glass Refers to glass blown with double walls and sealed after silvering of the enclosed surfaces; used to produce ornamental wares. aat:300311358 simetite A hard translucent red, yellow, orange, or brownish-yellow fossil resin, found in Sicily. Used for making jewelry and other ornamental objects. aat:300010828 single strength window glass Sheet glass with a thickness of 3/32 in. used for windows. Refers to red iron oxide or a similar pigment, particularly when it is a component of reddish-brown chalk or mixed with lime and water and applied with a brush to create aat:300013556 sinopia (pigment) underdrawings for frescoes. These underdrawings are called "sinopie." aat:300263391 sinter Siliceous or calcareous material deposited at the mouth of springs or geysers, along streams, or on lake bottoms or shores. Refers to a type of modern cast glass that is made by pouring molten glass into molds, creating a thick glass that may have a chipped or faceted surface. It is used aat:300262480 slab glass primarily in construction, for example, to create floors or windows set in concrete, sometimes resembling stained glass. It was invented in France around 1900 as a form of paving. aat:300010418 slag cement An artificial cement with hydraulic properties that is made by grinding together granulated blast-furnace slag and hydrated lime. aat:300010754 slag concrete Relatively lightweight concrete made with blast-furnace slag as the coarse aggregate. A very fine-grained, foliated, non-layered metamorphic rock, generally produced by metamorphism of shale under relatively low pressure and temperature. It occurs in aat:300011646 slate (rock) many varieties, including clay, hornblende, mica, talc slate, and others, all of which have the common property of splitting readily into thin plates. Fine clay which, when mixed with water, results in a fluid with a creamlike consistency, used in casting, glazing, decorating, and repairing ceramic wares; in its natural aat:300010459 slip (clay) state, it contains sufficient flux to be used for glazing and decorating without the need of additives. For ceramic glaze with a high content of slip, use "slip glaze." aat:300012990 slow-curing asphalt Cutback asphalt composed of asphalt cement and oils of low volatility and slow evaporation. aat:300266469 smalt (glass) Powdered glass that is colored deep blue by oxide of cobalt. After cooling, the glass is finely pulverized for use as a pigment or for brightening whites in laundry. aat:300209720 smectite Any of a group of expanding-laatice clay minerals, the chief constituent of bentonite and fuller's earth. Hard, dense, often shiny, mineral composed of zinc carbonate. Smithsonite was the principal source for zinc prior to 1880. It has been found in Greece, Germany, aat:300395586 smithsonite Austria, Poland, Italy, Rhodesia, and the United States. Smithsonite can be white, gray, green, blue, yellow, purple, pink, or brown. It occurs as a secondary mineral in the oxidized zones of hydrothermal ore deposits. Formerly confused with hemimorphite, and both were called calamine; see "calamine(mineral admixture)." aat:300010513 soap (brick) A brick or tile of normal face dimensions, having a nominal 2 in (5 cm) thickness. A water-dispersible cleansing and emulsifying agent produced by the saponification reaction of long chain faaty acids, such as found in oils and fats, with an alkali, such aat:300014329 soap (organic material) as sodium hydroxide or lye. Soaps made from animal fat and wood ashes have been used since antiquity. Although soap was made at home for laundry purposes from the European Middle Ages to early modern times, cake soap was a luxury product that came into common use only in the 19th century. A very soft rock composed primarily of hydrated magnesium silicate. It is easily cut and has been used for carvings since ancient times. It is usually a white, grayish green, brown or in rare cases, red or black. The stones were carved for bowls, boxes, and small objects such as figurines, beads, seals, amulets, and scarabs. In modern aat:300011665 soapstone (metamorphic rock) construction, it is used for laboratory sinks, bench tops, and electrical panels. Native soapstone is so soft it can be scratched with a fingernail, but baking results in dehydration and hardening of the stone. Some ancient soapstone carvings were glazed then fired, which produced the mineral enstatite, hard enough to scratch glass. Sections of earth together with the grass growing on them, held together with maated roots, usually square or oblong in shape and of moderate thickness, cut out or aat:300014358 sod (soil) pared off from the surface of grass land. aat:300010818 soda lime glass A lime glass in which soda is used. A soft, waxy, light, extremely malleable, silvery-white, unstable metallic element of the alkali group. It has the symbol Na in the periodic table and the atomic number 11. Sodium is the most common alkali metal and the sixth most abundant element on Earth. It appears only as a compound with other elements in nature. It has a aat:300265406 sodium (sodium) strong affinity for oxygen and other nonmetallic elements. It is highly reactive, burns with a yellow flame, oxidizes in air, and reacts violently with water. Sodium provides the chief cation (positive ion) of extracellular body fluids. It is an essential nutrient in animals; it helps to maintain blood volume, regulate the balance of water in the cells, and keeps nerves functioning. Grayish white poisonous powder once commonly used as an herbicide and insecticide but retired due to its high toxicity. It is currently used for preservation of color in aat:300380407 sodium arsenite zoological and botanical specimens; in taxidermy, as ingredient in soap used for cleaning and sterilizing hides. White, water soluble crystalline or granular powder, commonly known as baking soda or bicarbonate of soda. It is used as a leavening agent for baking; in medicine as aat:300379979 sodium bicarbonate an antacid; as a whitening agent in toothpastes; a fire retardant; a stain-absorbing ingredient in dry cleaning preparations. Chemical formula: NaHC03. aat:300380410 sodium bisulfite Water soluble white crystals or powder used as a disinfectant and bleach. Sodium bisulfite produces sulfur dioxide when heated. A white crystalline solid, usually encountered as a powder, used as a bleach for wood pulp, and as a versatile reducing agent which converts ketones and aldehydes to aat:300380411 sodium borohydride the related alcohols. An anhydrous grayish-white, odorless, water-soluble powder, NA2CO3, usually obtained by the Solvay process and containing about 1 percent of impurities consisting of aat:300183897 sodium carbonate sulfates, chlorides, and bicarbonates. It is used in the manufacture of glass, ceramics, soaps, paper, petroleum products, as a cleanser, for bleaching, and in water treatment. A water-soluble polymer, commonly known as carboxymethylcellulose (CMC), composed of the sodium salt of modified cellulose. A viscous gel when dispersed in water aat:300379876 sodium carboxymethyl cellulose at low concentrations, CMC forms a tough, non-soluble film in reaction with heavy metal salts. In conservation, it is used as an adhesive and as a poultice for cleaning stone. A crystalline compound, NaCl, found as colorless, cubic crystals that naturally occur in ocean water at concentrations of 2.6% and in the mineral halite. Sodium chloride is widely used for flavoring and preservation of food, for curing hides and skins, in electrochemical reactions and mordanting, in the precipitation of photographic aat:300183888 sodium chloride emulsions, and for many other purposes. For any substance resulting from the combination of negative ions from acids and usually metal ions, use "salt (inorganic material)." aat:300380011 sodium chlorite Chlorine compound commonly used as a bleaching agent for textiles and paper. aat:300210797 sodium compounds Substances composed by the chemical union of sodium with additional elements. Sodium dehydroacetate is the sodium salt of dehydroacetic acid. It is a preservative and antimicrobial agent that has been used as a food additive and in aqueous aat:300386728 sodium dehydroacetate deacidification of manuscripts. Sodium dithionite (also known as sodium hydrosulfite) is a reductive bleaching chemical. Usage includes iron stain removal, and occasionally to treat corroded copper aat:300375723 sodium dithionite and silver artifacts in object conservation. It can also be used for purification of water and gas and as a sulfonating agent or a sodium ion source in industrial processes. Colorless, odorless, crystalline salt used in very dilute solutions to fluoridate water and treat tooth decay. In higher concentrations, sodium fluoride is used as a fumigant, aat:300380408 sodium fluoride and a preservative for zoological specimens, paint, plaster, wood, and masonry. The salt of formic acid, sodium formate is used as a neutral buffering agent. It sometimes appears spontaneously as a layer of white crystalline efflorescence on sodium- aat:300380274 sodium formate rich glass artefacts exposed to the pollutant gas formaldehyde. Amorphous sodium polyphosphate used as water softener (marketed in powdered form as Calgon T and other copyrighted names), sequestering agent, and corrosion aat:300386729 sodium hexametaphosphate inhibitor. In conservation, sodium hexametaphosphate is used in the cleaning of wood, stone, textiles, and ceramics. A white, deliquescent, water-soluble solid, NaOH, usually in the form of lumps, sticks, chips, or pellets, that upon solution in water generate heat. It is used for the aat:300011726 sodium hydroxide manufacture of other chemicals, rayon, film, and in medicine as a caustic. aat:300380233 sodium lauryl sulfate Water-soluble anionic surfactant used in detergents and other cleaning products such as toothpaste. In conservation, used in the aqueous cleaning of painted surfaces. An inorganic compound used in the form of a white crystalline powder used variously as an antioxidant, a disinfectant, and a preservative in foods. In a conservation aat:300387533 sodium metabisulfite context, it has been used for removing rust stains from paper. Colorless, crystalline compound that forms naturally as caliche in mineral deposits, chiefly in Chile and Peru. Sodium nitrate is used in the manufacture of fertilizers, aat:300380568 sodium nitrate glass, and explosives. White hygroscopic crystals, the sodium salt of nitrous acid; used in dye manufacture, as a fixative for color photographs, a meat preservative, and as a corrosion aat:300380259 sodium nitrite inhibitor when applied to steel. White, odorless, water-soluble crystalline powder found in almost all laundry soaps. It is a mild alkaline oxidizing agent which serves to increase detergency. It is also aat:300380409 sodium perborate used as a deodorant and antiseptic. Dilute compounds of sodium perborate have been used in the conservation field to remove stains from textiles and other materials. A colorless, solid, water soluble carbonate perhydrate, sodium percarbonate is a highly concentrated source of anhydrous hydrogen peroxide used as a bleaching agent aat:300380251 sodium percarbonate in many applications including paper and textile conservation. A super-absorbent polymer, the sodium salt of polyacrylic acid, with broad commercial applications. In a conservation context, it is used as a moisture buffer material for aat:300387532 sodium polyacrylate humidity control in museum exhibit cases and in historic structures. A double salt of sodium bicarbonate and sodium carbonate, forming in white crystalline needles. It is used in the treatment of water for softening or cleaning aat:300380199 sodium sesquicarbonate applications. In conservation, used in solution to stabilize corrosion by removing chlorides and other salts from iron and bronze. A sodium compound which in its anhydrous form occurs in nature as a chemical precipitate found in the minerals thenardite and mirabilite. It may also be obtained aat:300379889 sodium sulfate synthetically by mixing sodium chloride and sulfuric acid. As a solid or powder, sodium sulphate is used in the manufacture of various products. In conservation science it is addressed as an agent of salt damage to stone. A chemical compound with the property of making silver salts water-soluble. This property was discovered by Sir John Herschel in 1819, who recommended it as a fixer aat:300389874 sodium thiosulfate in photographic processing. It is also used in conservation practice as a cleaning agent for silver and silver-gilt surfaces, and removing silver chloride from wet-washed paper and wet-washed textiles. A white, powdery inorganic compound, the sodium salt of the polyphosphate penta-anion. It is manufactured for use as an emulsifier and chelating agent in water aat:300386714 sodium tripolyphosphate softeners and detergents. In conservation it has been used as a sequestering agent for the treatment of excavated copper and bronze objects, a chelating agent in the conservation of paper objects, and as a surfactant in the cleaning of photographs. It has been suspected of contributing to water pollution. aat:300010610 soft brick Weak, non-weather-resistant brick fired at low temperature ranges or remote from the fire in the kiln; suitable for use as backing brick. Type of porcelain material comprising white china clay and powdered glass, which is substituted for the feldspathic rock used in hard paste porcelain. It is "soft fired" at aat:300010665 soft paste porcelain (material) the relatively low temperature of around 1200 degrees centigrade. After firing, it is characterized by being able to be cut with a file in unglazed areas, and having a translucency that is variable in intensity and color. A class of soft or semifluid soaps made by the saponification of oils, such as candlenut oil or olive oil, with potassium hydroxide. Soft soaps tend to dissolve more readily aat:300015164 soft soap in water than hard soaps. Apart from typical cleaning applications, it has been used as a parting compound to separate plaster casts from their molds. Lead alloy solder with tin, having a melting range usually between 130 and 180 degrees Celsius, with an upper limit of around 300 degrees Celsius; usually not used in aat:300242127 soft solder soldering precious metal. aat:300011775 soft water Water that is free from dissolved salts and such metals as calcium, iron, or magnesium. aat:300124111 soft-mud brick Brick produced by a process of forming wet clay in molds. aat:300014330 soil Unconsolidated material on the earth's surface formed by the weathering of rock and that portion of the earth's surface that can support plant life. aat:300014374 soil cement Portland cement mixed with the existing soil to serve as a paving or surfacing material. Any of various types of alloy, commonly of lead and tin, used in soldering; the primary requirement is that it have a lower melting point than the metal surfaces to be aat:300010993 solder joined. aat:300010525 solid brick A brick which meets the specifications for a solid masonry unit. Modified nylon developed by DuPont in the 1940's; formerly used in conservation as an adhesive and sizing agent for fragile paper, and as a consolidant for stone and aat:300379666 soluble nylon friable pigments. Its use was discontinued following the discovery that over time it becomes insoluble and opaque, and is unsafe to remove. Soluble salts are dissolved minerals whose crystallization on the surface and in the substrate of materials causes efflorescence and deterioration.The presence of water- aat:300379536 soluble salt soluble salts is a key factor in the degradation of masonry and other highly porous stone building materials. Surface efflorescence is a serious threat to ancient mural paintings. Conservation seeks to identify soluble salts in objects affected, and extract them or otherwise halt the degradation they inflict. aat:300014302 soybean oil A pale yellow drying oil obtained from soya beans. It is frequently used in paint and varnish, and sometimes mixed with linseed oil. Synthetic elastomeric fiber or fabric composed largely of alternating rigid and flexible segments of polyurethane. It is used in the clothing industry, especially for hosiery, aat:300310125 spandex underwear, swimwear, and other close-fitting garments. Spandex is the generic name in the United States and Canada. Elastane is the generic name used elsewhere. Lycra is a proprietary name for this material. aat:300010861 spandrel glass Clear glass with colored ceramic enamel fired on one side, used for spandrels and similar applications. A white, translucent wax composed of a mixture of faaty acid esters (cetyl palmitate) and long-chain alcohols, obtained from the the oil in the head cavity of the sperm whale, Physeter macrocephalus, other whales, or dolphins. It is created by the spermaceti organ inside the whale's head and connected to its nasal passage The substance was named in the mistaken belief that it was the coagulated semen of the whale. Spermaceti is collected from the cooled sperm oil, then washed with hot water and pressed to remove residual oil. The solid mass is then mixed with a slightly alkali solution and cast into molds. Spermaceti forms brilliant white crystals that aat:300014597 spermaceti are hard but oily to the touch, and are devoid of taste or smell. Spermaceti has been used since at least the 15th century for ointments, castings, soaps, cosmetic creams, fine candles, pomades, and textile finishing; later it was used for leather dressing and industrial lubricants. Space agencies in Europe and the United States still use spermaceti for roving vehicles on the moon and Mars and as lubricant on the Hubble space telescope. The biological function of the oil for the whale is uncertain, but among possibilities are that is used as a means of altering the whale's buoyancy, to focus sound waves to stun its prey, or as a cushion to protect the sperm whale's delicate snout while diving. Most spermaceti wax currently on the market is made synthetically. aat:300011267 sperone A type of peperino that is particularly hard and durable; quarried near Castiglione, Italy. aat:300014264 spike oil Oil distilled from an inferior grade of lavender. Oil of spike is used in painting on porcelain, in soap, scent, and food flavorings. aat:300389890 spinifex resin Refers to the gum extracted from perennial grass of the genus Triodia. Australian Aborigines harvest and produce the resin for use as an adhesive. aat:300010514 splay brick A brick, one side of which is beveled. aat:300247905 spodumene Mineral occurring in white, green, pink, yellowish, or purple prismatic crystals containing lithium oxide, used as a source of lithium, in ceramic flux, and in glassmaking. aat:300380347 spongolite A light, porous, siliceous sedimentary rock composed almost entirely of sponge spicules. Spongolite was much used as a building stone in medieval Bohemia. aat:300010518 squint brick A building stone or brick of special shape to be used at an oblique corner. Refers to glass of various colors created by adding metallic oxides to the molten glass; different oxides create various colors. Stained glass may be conbined with painted aat:300010853 stained glass (material) glass, which involves fusing pigment onto the surface. aat:300010920 stainless steel Any of a large number of iron-chromium alloys, widely used for their corrosion resistance and nonrusting quality. Heavy viscous material resulting from the polymerization of an oil, such as linseed oil; used chiefly in painting and glazing mediums; unlike raw oil, tends not to yellow aat:300014278 stand oil with age. aat:300266168 stannite A sulfide of tin, copper, and iron; an ore of tin. Substance made of carbohydrate granules of varying sizes obtained from roots, bulbs, and seeds of most plants. Starch is primarily obtained from rice, wheat, corn, potatoes, cassava (tapioca), sago, and arrowroot. It is a mixture of the soluble straight-chain amylose molecules and the insoluble, branched-chain amylopectin aat:300012959 starch molecules. When starch is heated, the granules swell and form a thick, tacky jelly upon cooling. Starchy adhesives have been used since at least 3500 BCE in Egypt. More recently starch has been used for sizing fabric, canvas, and paper, as an adhesive for paper cartons, bottle labels, gummed tape, and envelopes. Soluble starch has been used for priming canvas and as a binder in watercolor paints. Starch is sensitive to moisture and biodegradation. Starchy paste films become brittle with age. Bronze with a smooth, reddish surface, generally composed of 7 to 10% tin, 1 to 3% lead, and the remainder copper; used, for example, to make statues, plaques, and aat:300133724 statuary bronze hardware. aat:300011482 statuary marble Marble of the purest white and of finely crystalline form used in architecture and sculpture. aat:300011784 steam Water in the form of an invisible gas or vapor, changed to this form by boiling and used extensively for the generation of mechanical power. Any of various hard, strong, durable, malleable alloys of iron and carbon, often with other elements such as manganese, chromium, nickel, molybdenum, copper, aat:300133751 steel (alloy) tungsten, cobalt, or silicon; widely used as a structural material. Material derived by bonding stainless steel and aluminum alloy, for example, through diffusion bonding, friction welding, explode bonding, or using semisolid aluminum aat:300010928 steel-aluminum alloy alloy. A standard high-grade silver alloy with a minimum of 925 parts silver, the rest being copper for hardening purposes; used for the highest quality silver jewelry, aat:300010977 sterling silver tableware, and electric contacts. A soft, gray or black antimony sulfide mineral; the chief ore of antimony. In powdered form, it was occasionally used as an eye paint in Egypt from the Amarna period aat:300387605 stibnite onwards. aat:300124127 stiff-mud brick Brick made of clay mixed with only enough water to produce plasticity, and extruded through a die. aat:300380571 stilbene Colorless or pale yellow unsaturated crystalline hydrocarbon used in dyestuffs and as a fabric brightener. Vegetable oil obtained from a tree cultivated in China valued for its drying properties and is probably the traditional material used by Chinese artist to grind vermillion. It aat:300183914 stillingia oil was formerly used as an adulterant in Chinese tung oil. A term applied to any brick handmade with the aid of a brick stock, a wooden board on which a frame was placed to contain the clay; it is also used to describe the aat:300010648 stock brick ordinary brick of a locality. Stolzite is a lead tungstate, a rare secondary mineral that is nearly identical in chemical composition to wulfenite with which it is often associated in the oxidized zones of aat:300386718 stolzite tungsten-bearing lead deposits. It is named for Joseph Alexander Stolz of Bohemia who first identified it. General term for rock that has been cut, shaped, crushed, or otherwise formed for use in construction or other purposes. Includes the specific archaeological and aat:300011176 stone (worked rock) anthropological sense of individual stones which may be decorated or ornamented and which may be used in ritual contexts. These are usually not carved or dressed, and so differ from sculptures made from stone. aat:300011694 stone dust Pulverized stone used to fill the spaces between irregular stones and produce a stable surface. A brown, sticky, aromatic resin obtained from trees of the genus Liquidambar, including L. orientalis, native to Turkey. A white solid powder that forms in the steam aat:300375613 storax (resin) distillate obtained from storax is polystyrene. Storax resin is sometimes used as a mounting media for microscope slides. For the a brown, aromatic resin obtained from the genus Styrax, use "benzoin." Resins from both Sytrax and Liquidambar trees were formerly called "storax," but "storax" is no longer used for resin of genus Styrax. Refers to a type of glass that is blown from two colors combined in the molten state, creating streaks of various colors. It is often used to make windows, but may also aat:300263718 streaky glass be used to make vessels. It differs from "reamy glass" in that reamy glass generally contains white streaks and has the distinctive appearance of a colored liquid having been stirred into cream. Strontium (symbol: Sr) is a soft silver-white metallic element that turns yellow when exposed to air. Strontium is used commercially in luminous paint, fireworks and aat:300379545 strontium television tubes, and the compound strontium-oxide serves as a non-toxic replacement for lead in ceramic glazes. Paleontologists study strontium levels in human and animal bone for information about ancient diet. aat:300249798 strontium titanate Synthetic crystal formed by the flame fusion process that can be made to simulate a diamond. aat:300010694 structural clay tile A hollow clay tile composed of burnt clay, shale, fireclay, or mixtures thereof. Foams used to provide structure in packaging or for other applications such as furniture. Structural foams can be produced by injecting gases into a molten aat:300167540 structural foam thermoplastic under pressure in an extruder. Architectural glass introduced in the early 20th century used for interior and exterior wall surfaces. Products included glass building blocks, reinforced plate glass, and aat:300391182 structural glass pigmented structural glass known under such trade names as Carrara Glass, Sani Onyx (or Rox), and Vitrolite. Structural glass was a popular building material of the Art Deco period, and is no longer manufactured. aat:300011010 structural iron Iron that has been cast or worked in structural shapes. aat:300011653 structural slate Slate primarily used for general building purposes; such slate should be free from pits, cracks, or others defects that could affect its durability or strength. aat:300010931 structural steel Steel, rolled in a variety of shapes, such as beams, bars, or sheets, and used as load-bearing structural members. aat:300380573 studtite A yellow colored secondary uranium mineral containing peroxide. aat:300014498 styrene-acrylonitrile Copolymer plastic composed of styrene and acrylonitrile that has high thermal resistance. aat:300014408 styrene-butadiene rubber Synthetic rubber made by the copolymerization of two compounds (one being butadiene) and a catalyst (sodium). A fossil resin ranging in age from early Eocene to early Oligocene, originating in areas along the Baltic Sea and containing succinic acid (usually 3-8%). Around 40 aat:300012935 succinite (amber) varieties of amber are recognized, divided into two main groups: those containing succinic acid make up the succinite group and those having little or no succinic acid belong to the retinite group. A sweet crystalline carbohydrate, white when pure, obtained from a great variety of plant juices, but chiefly from those of the sugar-cane and sugar-beet, and forming aat:300183931 sugar an important article of human food. Compound that is a salt with the sulfate ion SO4 2-, or an ester of sulfuric acid. Sulfates comprise an enormous group of chemicals that contain the element sulfur. aat:300251553 sulfate Sulfates are used in a variety of common products and processes. aat:300010393 sulfate-resistant cement A portland cement low in tricalcium aluminate; has a reduced susceptibility to aatack by dissolved sulfates in water or soil. A compound of sulfur with another element (usually denoted by a qualifying term). Sulfide is used to describe any of three types of chemical compounds that contain aat:300156332 sulfide (material) sulfur: organic sulfides, inorganic sulfides, and phosphine sulfides. A salt of sulfurous acid, usually with a qualifying term indicating the base, such as magnesium sulfite, sodium sulfite, or copper sulfite. The sulfites are recognized by aat:300391381 sulfite their giving off the smell of sulfurous acid when acted on by a stronger acid. aat:300210820 sulfur compounds Substances composed by the chemical union of sulfur with additional elements. aat:300011770 sulfur dioxide A colorless gas used chiefly as a refrigerant, as a preservative, in bleach, and for making other chemicals; it is also a component of acid rain. Any of several gaseous compounds of sulfur and oxygen, most importantly sufur dioxide and sulfur trioxide. Sulfur oxides are responsible for about 18 percent of the aat:300380574 sulfur oxide total average pollutant content of air. aat:300391382 sulfurous acid Sulfur dioxide dissolved in water. Sulfuryl fluoride (SO2F2) is a toxic inorganic gas used as a structural fumigant insecticide to control dry-wood termites. It was developed by Dow Chemical Company in aat:300265417 sulfuryl fluoride the late 1950s and sold under the trade name "Vikane." It more recently has been used as a post-harvest fumigant for dry fruits, nuts, and grains, sold for this use under the trade name "ProFume." The earliest type of brick, it is baked in the sun rather than hardened by the heat of a fire. Sun-dried brick has the advantage of being less expensive than fired brick but aat:300081146 sun-dried brick is generally less durable; it is well-suited to dry climates. For sun-dried brick containing straw and other binders, use the more specific "adobe." Oil to which an equal amount of water has been added, perhaps salt water, shaken, and exposed to the sun in a glass jar or tray for a few weeks. The vessels are aat:300183925 sun-refined oil typically loosely covered to exclude dirt, but permit air. The oil and water must be recombined every day for the first week. Length of exposure time to the sun varies according to the season and to the intended consistency and color desired. At the end of the treatment, the oil is separated from the water by means of a funnel. Oils prepared by natural thickening in sunlight. This is most often a linseed oil. Sun-thickened oil is similar to stand oil, but is prized for is fast-drying properties as a aat:300014284 sun-thickened oil painting medium. aat:300014304 sunflower oil A pale yellow drying oil with a pleasant odor and taste obtained from the large seeds of the common sunflower plant. An enzyme that catalyzes the dismutation of superoxide into oxygen or hydrogen peroxide. It works as an antioxidant, and has also been used to catalyze the aat:300404874 superoxide dismutase peroxidation of various compounds and as a scavenger of carbon radicals in carbonized silk fabrics. A phanoerocrystalline intrusive igneous rock composed mostly of alkaline feldspar with or without a smaller amount of plagioclase and without notable quartz or aat:300011220 syenite nepheline content. The term can also refer to a granite varietal, quarried in antiquity at Syrene in Upper Egypt, in which biotite is substituted for or accompanied by hornblende. A colorless or white mineral consisting of potassium chloride, occurring typically as cubic crystals. It is rarer than halite (sodium chloride) and occurs as soft, bitter- aat:300386503 sylvite tasting, white or grayish, glassy cubes or as masses with halite and gypsum in evaporite deposits in Germany, New Mexico, and Mount Vesuvius. Syngenite is a hydrous sulfate of calcium and potassium occurring in tabular crystals. It is sometimes found as a salt deposit on masonry surfaces, a gray-white bloom aat:300380346 syngenite on walls facing the prevailing wind and rain. aat:300378967 synthetic resin Resin having a polymeric structure, that is, formed by a chemical reaction between two or more substances; used chiefly in plastics. aat:300010423 tabby (cement) A mixture of lime and water with shell, gravel, or stone which, when dry, is as hard as rock; used as a building material. Sodium chloride crystals prepared for use as a food seasoning and preservative. Table salt contains sodium chloride with small amounts of a free-flowing agent (calcium aat:300386506 table salt silicate or magnesium carbonate), an anti-caking agent (sodium ferrocyanide), an iodizing salt (potassium iodide or sodium iodide), and an iodide stabilizer (sodium carbonate and sodium thiosulfate). aat:300011259 tachylite Volcanic glass of basaltic composition from Oahu, Hawaii; it is used for making various ornamental objects. aat:300011159 talc (mineral) Soft light green or gray mineral. It is used for cosmetics, paper coating, and as a filler for paints and plastics. Black, resinous faaty by-product from the kraft paper pulping of pine wood. In addition to being an important source of rosin, tall oil is used in the manufacture of soaps, aat:300386654 tall oil resins, greases, inks, and other materials. A hard fat obtained from animals, especially sheep, goats, and caatle, containing the faaty acids oleic acid, palmitic acid, stearic acid, linoleic acid, and myristic acid. aat:300182830 tallow Tallow is used in leather dressing and in the manufacture of soaps, lubricants, candles, and food. Variety of Maori pounamu stone that is clear like glass, and ranges in color from olive-green to bluish-green. It is the stone used earliest as pounamu. The composition is aat:300379308 tangiwai (stone) typically bowenite rather than nephrite. Most tangiwai is comes from two isolated areas at Piopiotahi (Milford Sound). Water drawn through taps from pipes in a dwelling or other structure. Due to its noncorrosive properties, tap water may be used in conservation of ancient stone aat:300375716 tap water materials in preference to distilled water. aat:300014368 tapia Clay with a component of fine gravel used to make bricks or otherwise puddled, rammed, and dried. Primarily used for wall construction. Thick, viscous, brown or black, inflammable liquid residue resulting from the partial evaporation or distillation of wood (such as pine, fir, or larch), sugar, tobacco, peat, coal, or other organic substance. It contains hydrocarbons, resins, alcohols, and other compounds; it has a heavy resinous or bituminous odor. It is used as an aat:300012991 tar (material) antiseptic, for coating asphalt roads, preserving timber, caulk on wooden sailing ships, waterproofing for roofing papers, insecticide, in disinfectant soaps. Some tars, such as those obtained from pine or beech wood, have been mixed with linseed oil to form a dark brown glaze and for other purposes. aat:300011607 tasio A white marble with a bluish tinge from the island of Thasos in the Aegean Sea; it has a compact texture and sparkling crystals. Bricks of larger than normal dimensions made to evade the early brick tax in England, which was levied simply on the number of bricks manufactured. Subsequent aat:300010494 tax brick legislation eliminated the advantage of using such bricks (which were more difficult and expensive to use anyway); thicker than usual bricks remained in use, however, particularly in the North and Midlands. aat:300391212 tektite Refers to any of various green to brown silicate glass materials formed when a meteorite impact melts the local rock. A copper arsenic sulfide mineral found in hydrothermal veins and contact metamorphic sites, usually containing some antinomy and grading into closely related mineral aat:300387566 tennantite tetrahedrite, in which antinomy takes the place of arsenic. It is a minor ore of copper. aat:300380345 tenorite Gray or black crystalline copper oxide mineral found as earthy masses in copper deposits and as thin metallic scales on lava as at Vesuvius and Etna. aat:300404934 teocuitlatl Gold or silver. This term was oftern modified with "coztic," yellow, to mean gold, or "iztac," white, to mean silver. A baked or semi-fired material that is usually a mixture of clay, grog, and water; it has been used for pottery, statuettes, lamps, roof tiles, and cornices since ancient aat:300010669 terracotta (clay material) times. It may be glazed prior to firing. To produce an item, terracotta is molded or shaped, dried for several days then fired to at least 600 C. It is fireproof, lighter in weight than stone, and usually brownish red in color. aat:300011696 terrazzo Marble aggregate concrete that is cast in place or precast and ground smooth; used especially as a decorative surfacing on floors and walls. Refers to a white lead-glazed 'faïence fine' introduced by Jacques Chambrette at Lunéville in 1748 and there used unglazed for biscuit figures and groups and as a aat:300375530 terre de Lorraine pipe clay. aat:300380545 tetrachloroethylene Colorless, nonflammable chlorinated hydrocarbon used widely as a dry cleaning solvent and an industrial degreaser. A copper antinomy sulfide mineral found in hydrothermal veins and contact metamorphic sites, usually containing some arsenic and grading into closely related mineral aat:300387568 tetrahedrite tennantite, in which arsenic takes the place of antinomy. It is a minor ore of copper. aat:300390604 textile-reinforced concrete Reinforced concrete that contains embedded textile material reinforcements instead of the typical metal bars. aat:300380395 tezontle Porous volcanic stone, a dark reddish pumice, used as a construction and building material in Mexico since prehistoric times. A white, amorphous mineral composed of silicate, carbonate, and calcium sulfate. It is often formed by the reaction of sulfates and concrete or mortar. Thaumasite aat:300380047 thaumasite crystal formation induces sulfate decay in the cement paste matrix. Conservation interventions seek to remove thaumasite or limit its aatack. Plastic that becomes soft when heated and hard when cooled, no maater how often these processes are repeated, because of little or no cross-bonding between aat:300014415 thermoplastic molecules. aat:300167631 thermoplastic polyester Melt-processible plastics made with polyester, such as beverage bottles and microwaveable food trays. aat:300167627 thermoplastic polyimide Polymers that continually soften upon heating and harden upon cooling. A polymer with strong intermolecular bonding that becomes rigid by chemical reaction and that is not remeltable. Thermoset polymers are usually insoluble in most aat:300014515 thermoset solvents. Examples of thermoset polymers are epoxies, silicones, and phenolics along with some polyesters and polyurethanes. aat:300167629 thermoset polyester Heat-resistant resins or plastics made of polyester. aat:300167625 thermoset polyimide Heat-resistant polymer used commonly in films and coatings. Pure metallic element having symbol TH and atomic number 90; a radioactive, soft, silvery metal most often extracted from the phosphate mineral, monazite. Use also aat:300379770 thorium for this metal as processed and formed, usually in combination with other substances, to make various objects and materials. Pure metallic element having symbol Sn and atomic number 50; a soft, pliable, silvery white metal. Use also for this metal as processed and formed, usually in aat:300133748 tin (metal) combination with other substances, to make various objects and materials. aat:300010978 tin alloy Alloy in which tin is the principle component. aat:300133203 tin brass Copper-zinc alloy with a small amount of tin which improves corrosion resistance. aat:300380231 tinplate Thin, protective coating of tin applied to sheet iron or steel by electroplating or dipping. aat:300011612 tirio A bluish white marble that is slightly peppered brown and mottled; it is from Mount Lebanon, near Tyre (modern day Sur in Lebanon). Pure metallic element having symbol Ti and atomic number 22; a hard, lustrous, silvery metal. Use also for this metal as processed and formed, usually in combination aat:300011033 titanium with other substances, to make various objects and materials. aat:300010929 titanium steel Material made by the bonding of metallurgically incompatible titanium and steel, by explosive bonding or another method. aat:300014305 tobacco seed oil Vegetable oil made from tobacco seeds and used as a drying oil. It has an iodine value of 140 to 146. A thick, brown oleoresin obtained from Myroxylon balsamum var. balsamum trees that are native to the high plains of Venezuela, Columbia and Peru. Tolu balsam is used for perfumes, chewing gums, as a dark brown transparent glaze for paintings. It is similar to Peru balsam and derived from a variety of the same species. A thick, brown aat:300012907 tolu balsam (balsam) oleoresin obtained from Myroxylon balsamum var. balsamum trees that are native to the high plains of Venezuela, Columbia and Peru. Tolu balsam is used for perfumes, chewing gums, as a dark brown transparent glaze for paintings. It is similar to Peru balsam and derived from a variety of the same species. aat:300196199 tombac (alloy) An alloy of a brassy nature generally containing 85 to 88% copper and 12 to 15% zinc, and sometimes arsenic; used for coins, buttons, jewelry, and gilding. Material made from hard, bone-like structures grown in the mouth of vertebrates; distinguishable from other bone by its structure. Animal teeth, such as from aat:300011855 tooth (material) hippopotami, whales, lions, dogs, boars, bears, and humans have been used to make jewelry, gaming pieces, buttons, and and other items. An aluminum silicate containing fluorine that is formed by fluorine-bearing vapours given off during the last stages of the crystallization of igneous rocks. The topaz that is valued as a gemstone occurs in prismatic crystals that are transparent and lustrous, of white (colorless), yellow, brown, pale blue, pink, red, or pale green color, found aat:300011162 topaz (mineral) in Brazil, Mexico, Saxony, Scotland, Japan, the Ural Mountains, and elsewhere. Colorless topaz may be mistaken for diamond when brilliant cut. Colored topaz may be unstable and bleached by sunlight. It is believed that the topaz identified by modern mineralogists was unknown to ancient Greece and Rome and the writers of the Old Testament; the stone called "topazos" by the ancients was probably the minerals chrysolite, peridot, or yellow sapphire. aat:300010630 torchis Clay amalgamated with straw or pebbles to make an impasto that is used in building, particularly primitive domestic architecture. A velvety-black variety of cryptocrystalline quartz, siliceous shale, or similar substance used by jewelers for testing the purity of precious metal, especially gold, by the aat:300011149 touchstone streak left on the stone when rubbed with the metal. aat:300011163 tourmaline A mineral that occurs usually in 3-, 6-, or 9-sided prisms vertically striated but sometimes in compact or columnar masses. aat:300379783 trachyte A class of volcanic rocks, light in color and density, chiefly composed of alkali feldspar in which a small amount of quartz or oligoclase may also be present. aat:300011262 trass Volcanic material found in the Rhine district of Germany that is similar to pozzolan cement. A dense, crystalline or microcrystalline limestone that was formed by the evaporation of river or spring waters. It is named after Tivoli, Italy ("Tibur" in Latin), where aat:300011329 travertine large deposits occur, and it is characterized by a light color and the ability to take a good polish. It is typically banded, due to the presence of iron compounds or other organic impurities. It is often used for walls and interior decorations in public buildings. It is distinguished from "tufa" by being harder and stronger. Crystalline sugar, a disaccharide, stored instead of starch in some fungi, algae, and insects. Industrially manufactured trehalose has been used in combination with aat:300380337 trehalose lactitol as a sugar-alcohol saturation treatment in the conservation of archaeological waterlogged wood. aat:300209738 tremolite A white-to-dark gray monoclinic mineral of the amphibole group; it is a constituent of much commercial talc. A chemical compound; in conservation, a chelating agent of ammonium salt of citric acid used in solution for surface cleaning of paper, paintings, and other materials. aat:300380058 triammonium citrate May also be used as a buffering agent, preservative, and food additive. Naturally occurring lipid found in plants and animals, triglyceride is a chemical compound in which three molecules of a faaty acid are united by oxygen to one molecule aat:300380195 triglyceride of glycerol. Triglycerides function as stores of energy and are the chief components in most animal and vegetable fats and oils. Triglycerides are named according to faaty acid components, e.g. stearin is the triglyceride of stearic acid. aat:300380577 triphosphate Any salt or ester containing three phosphate groups. Calcareous, porous limestone formed by the precipitation of calcium carbonate at the vents of springs and geysers, along streams, or on the bottoms or shores of lakes. aat:300011712 tufa It is distinguished from travertine by generally being soft and easily crumbled. aat:300011264 tuff Rock composed of the finer kinds of volcanic detritus. A gold-copper alloy, of wide range of composition and color, resulting in a lower melting point than either contributory metal; widely employed in Central and South aat:300248834 tumbaga (alloy) America. aat:300014307 tung oil A semidrying oil used in hardwearing varnish and enamel. Pure metallic element having symbol W and atomic number 74; a heavy white metal with a specific gravity of 19.6 and the highest melting point of any metal. Use also aat:300011034 tungsten for this metal as processed and formed, usually in combination with other substances, to make various objects and materials, particularly alloy steel and magnets, and in electronic applications. aat:300386702 turmeric oil Oil derived from turmeric (Curcuma longa), a tuberous rhizome of the ginger family. A sticky, viscous yellow sap obtained from conifers. The crude turpentine contains about 65 percent rosin (solid residue) and 18 percent oil of turpentine (volatile aat:300375603 turpentine (resin) portion). It is distilled to create the volatile oil of turpentine, usually shortened to "turpentine (oil)." aat:300011164 turquoise (mineral) A triclinic mineral of blue, blue green, or yellowish green color. Material made from tusks, which are large protruding teeth found in elephants, walruses, narwhals, and boars. Tusks, like other teeth, have a soft center surrounded by aat:300011856 tusk (material) hard dentin primarily composed of calcium hydroxyapatite with smaller amounts of calcium carbonate, calcium fluoride, magnesium phosphate, and ossein. A hard durable enamel forms a smooth outer surface. Tusk has been used to make sculptures, handles, and other items. aat:300235496 type metal An alloy for making printing type, consisting chiefly of lead and antimony, and sometimes small quantities of other metals. aat:300220056 ultrapure water High-purity water used by the semiconductor industry, containing no electrolytes other than hydrogen and hydroxide ions. aat:300014575 unfilled plastic Plastic formulations that are not adulterated with fillers such as particles or fibers to increase stiffness or strength. Clay used as a medium, typically dried but not intended to be fired. Examples include ancient clay tablets that were inscribed, dried, and then soaked in water for the aat:300404797 unfired clay purpose of reforming and reuse, and some clay surfaces used for wall paintings. For pottery in a state that is not yet fired, but firing is intended, use "greenware." For bricks used as a building material but not fired, use "soft brick" or "sun-dried brick." Pure metallic element having symbol U and atomic number 92; a radioactive, silvery metal. Use also for this metal as processed and formed, usually in combination with aat:300011035 uranium other substances, to make various objects and materials. aat:300211732 uranium glass Type of glass made from the inclusion of uranium in the batch and yellowish-green or greenish yellow in color. aat:300014529 urea-formaldehyde resin Resin made by condensing urea or thiourea with formaldehyde. Copolymers of diisocyanate with polyester or polyether. Urethane is the strongest available elastomer, and has good abrasion resistance. Applications include parts aat:300014414 urethane elastomer (organic material) requiring high wear resistance, such as wheels, heels, and bumpers. A hard, insoluble coating prepared from the resinous exudation of Toxicodendron vernicifluum and Toxicodendron succedaneum, native to China and Japan. It contains urushiol, hydrourushiol, some polysaccharides, laccase, and water. It thickens and solidifies by oxidative polymerization when exposed to humid air, forming a hard, aat:300265172 urushi durable film that takes a high polish or may have a maate finish, and may be carved or inset with inlays. It has been used for at least 6,000 years as a protective and decorative coating, applied to wooden furniture, musical instruments, weapons, jewelry, and household items. aat:300010721 valley tile Tile used for roofing, distinguished by being shaped and laid to form a valley. Pure metallic element having symbol V and atomic number 23; a pale gray metal with a silvery luster. Use also for this metal as processed and formed, usually in aat:300011036 vanadium combination with other substances, to make various objects and materials, particularly steel. aat:300011372 variegated limestone Limestone that is streaked or marked with a different color or colors. aat:300011533 variegated marble Marble that is streaked or marked with a different color or colors. Pale to emerald green orthorhombic hydrated aluminum phosphate mineral. It is formed by phosphate bearing water reacting with aluminum rich rocks. Variscite is aat:300386476 variscite sometimes used in jewelry as a semi-precious stone. Repetitive sedimentary rock stratification-formed over the course of a year reflecting seasonal sedimentation variations, usually alternating finer and coarser layers (or aat:300380254 varved clay ‘varves’) of sand or clay which often exhibit contrasting colors. One of three naturally occurring crystalline mineral forms (or polymorphs) of calcium carbonate. The other forms are aragonite and calcite. Spherical precipitates of aat:300380334 vaterite vaterite have been recognized on microbial mats and biofilms in volcanic substrates as found in Roman catacombs. aat:300014258 vegetable oil Oil extracted from plant parts, such as seeds, fruits, or nuts. They contain a mixture of glycerides and may be considered drying, sem-drying, or nondrying. Low melting mixtures of long chain hydrocarbon compounds found in or on plants. Vegetable waxes contain faaty acids or alcohols along with the hydrocarbon series. aat:300014607 vegetable wax Vegetable wax properties range widely from the soft, white Japan wax to the hard, yellow of carnauba wax to the brownish black bitumen wax. They are used for cosmetics, leather dressing, and other purposes. A light or dark green massive serpentinite, commonly with veinlets of calcium carbonate and magnesium carbonate. It is capable of being polished and is commercially aat:300171549 verd antique considered a marble; it is also considered to be among the highest-quality serpentinites. aat:300011637 verde di Genoa A verd antique from Genoa, Italy that was first used by the ancient Greeks and Romans and continues to be used in modern times. aat:300311577 verde di Levanto (serpentinite) A serpentinite from the Italian Riviera having a green color. An Italian verd antique from Pegli, Italy that was first used by the ancient Greeks and Romans and continues to be used in modern times. It is a breccia marble aat:300011636 verde di Pegli consisting of deep green fragments of serpentine cemented by light green calcite. aat:300011639 verde di Ponsevera A serpentinite from Ponsevera, Italy, near Genoa. It is usually green with white veins, the green ranging from light green to metallic green to bluish green. A soft Italian verd antique from Prato, Italy that is deep olive green with dark green spots and veins of clear green and white. It was first used by the ancient Greeks and aat:300011640 verde di Prato Romans and continues to be used in modern times; it was notably used for much of the exterior decoration of the cathedral in Florence. aat:300011641 verde ranocchia A serpentinite of varying yellowish green hues, often with fine markings of black or gray; it is named for its frog-like markings. A base metal, usually silver, copper, or bronze, that has been coated with a transparent orange-red lacquer to produce a rich gold-colored finish that appears to be gilt. aat:300011044 vermeil (laquer-coated metal) Vermeil was common in the 19th century but rarely used today. For gold-plated silver, use "silver gilding." A group of micaceous clay minerals closely related to chlorite and montmorillonite; vermiculite is derived from the alteration of biotite and phlogopite in the zone of aat:300011128 vermiculite weathering. Synthetic pigment composed of red mercuric sulfide, chemically the same as the natural mineral cinnabar. There are two methods for preparing vermilion, a dry-process and a wet-process. The dry-process method, adding mercury to molten sulfur, was invented by the Chinese then imported to Europe ca. 8th century, seemingly via the aat:300013568 vermilion (pigment) Islamic world. The wet-process method, placing the ground black mercuric sulfide isomorph into a solution of ammonium sulfide or potassium sulfide, was developed in the late 17th century in Germany. Vermilion is a dense pigment with excellent hiding power, used in oil, watercolor, egg tempera, and fresco paintings. When exposed to ultraviolet light and oxygen, or chloride ions, vermilion can change from its normal red crystalline form to gray or black, resulting in dark discolorations. Blue-green monoclinic crystalline mineral, a hydrated basic phosphate of copper and zinc. Technical examination in 2008 revealed that veszelyite was used as a pigment aat:300380338 veszelyite in mosaic and polychrome masks and funerary offerings from the royal tombs of Calakmul, Mexico. Generic term for materials derived from vinyl chloride, vinyl acetate, or vinylidene chloride. Commonly used with reference to all polymers and copolymers of which vinyl aat:300014502 vinyl chloride is a constituent. Use more precise terminology for known materials such as "polyvinyl chloride" or "polyvinyl acetate." aat:300266730 vinyl copolymers Polymers created by combining two separate monomers from the vinyl group, vinyl acetate and vinyl chloride, for example. General term for materials derived from the polymerization of a monomer from the vinyl group. For materials derived from more than one monomer of the vinyl group, aat:300266731 vinyl polymers use "vinyl copolymer." Any member of a family of thermoplastic synthetic resins that may vary from liquids to rigid solids, created by the polymerization of ethylene derivatives or vinyl aat:300266729 vinyl resin compounds; generally vinyl acetate, vinyl chloride, and vinylidine chloride. Vinyl resins produce clear, hard films and are also used as coatings and adhesives. Mineral comprising naturally occuring ferrous phosphate. Vivianite was described after discovery in the St. Agnes mine in Cornwall in 1817. Used in the pigment "blue aat:300395684 vivianite (mineral) ocher"; has been found in Roman paint residues. Ferrous phosphate is used as a colorant in ceramics. A volcanic igneous rock of vitreous or glassy texture; it is a natural glass produced by the cooling of molten lava, or some liquid fraction of it, too quickly to allow aat:300263800 volcanic glass crystallization. Vulcanite is as an old trade name for a dark, brittle, moldable hard rubber that was produced by heating (‘vulcanizing’) a preparation of india rubber and sulfur. It aat:300380359 vulcanite was marketed in the U.S. as vulcanite and in England as ebonite. Vulcanite was used for small items such as buttons, brooches, and combs, finishes on camera bodies, and for insulation. aat:300014310 walnut oil A yellowish drying oil used especially for artist's paint. A liquid made up of molecules of hydrogen and oxygen (HO2). When pure, it is colorless, tasteless, and odorless. It exists in gaseous, liquid, and solid forms; it is liquid at room temperature. It is the liquid of which seas, lakes, and rivers are composed, and which falls as rain. Water is one of the most plentiful and essential of aat:300011772 water (inorganic material) compounds. It is vital to life, participating in virtually every process that occurs in plants and animals. One of its most important properties is its ability to dissolve many other substances. The versatility of water as a solvent is essential to living organisms. The term "water" is typically used to refer to the liquid form of this compound; for the solid or gaseous forms, use "ice" or "water vapor." aat:300010638 water-struck brick Brick formed in molds that have been watered in order to prevent the brick from sticking; brick formed in the slop molding method. Any solid or semi-solid substance that is slightly greasy to touch, usually solid, translucent, and has a low melting point; waxes are not a chemically homogeneous group. Waxes are composed of long chain hydrocarbon compounds, and may contain esters of faaty acids and alcohols, are thermoplastic and melt at low temperatures aat:300014585 wax of between 40 and 100 C. In general, waxes are water-repellent, smooth, soluble in organic solvents, and classified as animal (e.g., beeswax), vegetable (e.g., bayberry), mineral (e.g., paraffin), or synthetic (e.g., polyethylene). Waxes are used for polishes, candles, crayons, sealants, coatings, adhesives, waterproofing, carbon paper, media in encaustic and wax emulsion paintings, and as repellents in wax-resist watercolor paintings. A combination of wax and resin used as a preservative, adhesive, and in thermal transfer technologies. In the conservation of paintings, it has been used reinforce works aat:300379360 wax-resin by applying a paper or fabric lining aatached with a wax-resin. aat:300010698 weather tile Any of a series of tiles covering a wall and overlapped like shingles. A mineral consisting of calcium oxalate dihydrate found as tiny white, glassy crystals. Originally found in mud at the bottom of the Weddell sea, Antarctica, which gave aat:300386649 weddellite the mineral its name. Weddellite, and whewellite form on the surface of carbonaceous minerals in the presence of microbiological organisms such as lichens. A white to colorless mineral composed of calcium oxalate monohydrate. Whewellite is formed on the surface of marble and limestone due to the presence of microorganisms, such as lichen. It also occurs in geodes, or septarian nodules; associated with coal measures and surrounding rocks with organic material, and in some aat:300393147 whewellite uranium deposits. As microscopic crystals in living plant cells and as calculi or as a sediment in the human urinary tract. Named for William Whewell an English naturalist, scientist, and inventor of the system of crystallographic indexing. The term for a class of white alloys used by jewelers as substitutes for platinum; it is easily manipulated into intricate shapes. The name does not convey the relative aat:300010968 white gold value of the different grades, which vary a great deal. Typical white gold alloys consist of 20 to 50% nickel with the rest being gold; zinc, silver, copper, platinum, and palladium may also be used. aat:300011009 white iron A hard silvery-white cast iron or pig iron that has its carbon content almost completely in combined form; can also refer to thin sheets of iron coated with tin. aat:300011571 white marble Marble with a mineral composition resulting in a predominantly white color. aat:300010998 white metal Alloy predominantly of tin, usually of 92% tin and 8% antimony, having a white or silvery appearance. aat:300014921 white shellac Made by bleaching orange shellac with alkali. aat:300015324 whiting (chalk) Chalk that has been ground and washed for use in paint, ink, and putty. aat:300010654 wire-cut brick Brick cut to size by a wire before firing. aat:300010889 wired glass Sheet glass in which wire mesh is enclosed as a safety measure: when the glass is fractured the pieces are held together by the wire. Naturally occurring mineral composed of barium carbonate usually found in hydrothermal veins associated with barite. It is mined in Germany, England, Scotland, aat:300266846 witherite Canada (Ontario) and the U.S. (Illinois, California, Arizona). Witherite is used in case-hardening steel and in refining sugar. It is also used as a pigment in the manufacture of paints, glazes, and synthetic marble. A traditional crucible steel of southern India used for wire and sharp edged tools. Although associated in the popular imagination with Damascene swords, and aat:300380028 wootz legendarily a supersteel, wootz has a brittle structure subject to shaatering, making it more suitable for ceremonial blades than for actual use in baatle. aat:300011652 wrestler slate Roofing slate developed in the Lake District of England that is so called because the pieces interlock at the ridge thus eliminating the need for special ridge pieces. Iron alloy of fibrous nature made by melting white cast iron, passing an oxidizing flame over it, and rolling it into a mass; valued for its corrosion resistance and ductility. aat:300011012 wrought iron (iron alloy) When describing objects produced or shaped by beating with a hammer, use "wrought." A crystalline or granular mineral consisting of a molybdate of lead and ranging in color from orange-yellow to olive green or darker. It can be used as a yellow pigment aat:300404737 wulfenite (mineral) and in making molybdate red and orange pigments. aat:300010891 x-ray protective glass Glass that contains a high percentage of lead oxide and sometimes barium oxide, which offers sufficient protection from x-rays. aat:300380341 xenon A heavy inert noble gas with symbol Xe or X and atomic number of 54, used principally in lamps, lasers, and as a general anaesthetic. aat:300011618 yellow marble Marble that is predominantly yellow in color. Rare metallic element, the penultimate in the lanthanide series, having the symbol Yb and atomic number 70. Ytterbium is a soft, lustrous silver-white metal. Some of its aat:300380358 ytterbium isotopes generate gamma rays when irradiated and are used as a radiation source-substitute for portable X-ray machines. Chemical element having symbol Y and atomic number 39. Yttrium resembles lanthanide metals very closely and is often classified as a ‘rare earth element.' aat:300380580 yttrium Yttrium’s most important use is for making the phosphors used in television screen displays and in LEDs. Yttrium phosphors emit a clear red light when excited by electrons. aat:300014354 zaccab Fine white clay mixed with lime; used chiefly as building and plastering material, and for sculpture. aat:300386637 zein An alcohol soluble protein from maize, analogous to gluten, used in making textile fibers, plastics, adhesives, coatings and sizes. A large and varied class of crystalline metal aluminosilicate minerals containing loosely held water molecules. They are often found in the cavities of igneous rocks. aat:300379647 zeolite Specialized zeolite matrices can be prepared by varying heat and pressure to aluminum oxide and silicon dioxide. Zeolites have numerous technical applications; e.g., as ion exhange resins, absorbents, or molecular sieves. Pure metallic element having symbol Zn and atomic number 30; a bluish white crystalline metal. Use also for this metal as processed and formed, usually in combination aat:300011037 zinc with other substances, to make various objects and materials. aat:300011000 zinc alloy Alloy in which zinc is the principle element. An infusible, insoluble white solid oxide of zinc (ZnO) in the form of a fine white powder used in compounding rubber, as a fungicide, as an absorber of ultraviolet radiation, in pharmaceuticals, in cosmetic preparations, in pigments, as a component in paint to toughen and prevent yellowing, as a semi-conductor, in photocopying aat:300311583 zinc oxide processes (related to its photoconductivity), and in ceramic glazes, printing inks, glass colorants, enamels, and lubricants. Zinc oxide is prepared in either of two ways: by the oxidation of pure zinc or by roasting zinc ore. Zinc oxide has been used for various purposes since the Middle Ages, but was rarely used in making pigments until the 19th century. aat:300011165 zircon Mineral which has various colors and is a common accessory mineral in siliceous igneous rocks, crystalline limestone, schists, and gneisses. Zirconium is a metallic element having symbol Zr and atomic weight 91.22. It is obtained from zircon and other minerals and is commercially the most important ore. A aat:300380041 zirconium hard metal resistant to heat and corrosion, it is much used in nuclear reactors, in alloys, refractories, and ceramics. aat:300133255 Babbitt metal The original name for tin-antimony-copper alloy used for machinery bearings. It is now used for almost any bearing alloy with either a tin or lead base. aat:300011388 Hudson bluestone A bluestone that is quarried extensively near the Hudson River in New York for use as flagstone. A hard and highly crystalline marble from Missouri that is used extensively for interior and exterior applications; it is grayish in color, has a close, even texture and takes aat:300179366 Napoleon gray marble a high polish. Crinoide remains create pencil-like markings which in turn create aatractive paaterns that are revealed when the marble is sawn crossways. Basalt that has chemically changed over time to become a type of soapstone that is blackish-green when cracked open; it is found in the Blue Ridge and Piedmont aat:300011669 Virginia greenstone regions of Virginia. Pure metallic element having symbol Al and atomic number 13; a hard, strong, silver white metal. This metal is also processed and formed, usually in combination with aat:300011015 aluminum (metal) other substances, to make objects and materials. When not further qualified, the term refers to aluminum-copper alloy with or without small amounts of other alloying elements. Due to the influence of even tiny aat:300010936 aluminum alloy amounts of other elements on aluminum, there is an infinite variety of aluminum alloys. aat:300391084 aluminum foil Aluminum in the form of thin, flexible sheets or on rolls, used especially for wrapping or covering food. aat:300010938 aluminum-zinc alloy Alloy created with aluminum and zinc. aat:300249963 blister steel Steel made with wrought iron bars heated in charcoal for carbon impregnation. aat:300011386 bluestone A type of bluish-gray feldspathic sandstone that is dense, fine-grained and splits easily into thin smooth slabs; for this reason it is often used as flagstone. aat:300011403 brownstone (material) A brown or reddish-brown sandstone whose grains are generally coated with iron oxide. aat:300010470 bullnose brick A brick having one rounded corner, used where a sharp arris would be inconvenient or liable to damage. aat:300014288 candlenut oil Oil used as a substitute for linseed oil. Thermoplastic molding materials prepared from casein, a natural phosphorous-containing protein found in milk. While trying to make a waterproof coating in 1897, Adolph Spitteler and associate W. Krische of Germany discovered that casein becomes hard and insoluble when treated with formaldehyde. Casein plastics were used for aat:300014532 casein plastic small items such as buttons, beads, buckles, combs, fountain pens, umbrella handles, cutlery handles, and knitting needles; they are often pigmented to simulate ivory, horn, or tortoise shell. aat:300011278 claystone Fine-grain rock largely composed of or derived by erosion of sedimentary silt and clay or any type of rock that contained clay. aat:300380332 colored glass Glass created by various techniques but characterized by being uniformly colored as opposed to having a painted surface. Brick specially made for use where two walls join at an obtuse angle, so as to avoid the use of cut bricks with straight joints and an uneven arris (the sharp edge of a aat:300010492 dogleg brick brick). Generic term for glass fibers, glass fabrics, and resins reinforced with glass fibers; fiberglass is strong, lightweight, nonflammable, with a high tensile strength. The material dates to 1893, when spun glass fibers were made into fabric by Edward D. Libbey and exhibited at the Columbian Exhibition in Chicago. Owen-Corning aat:300183781 fiberglass developed several processes for making fine, continuous glass fibers in the 1930s, which were sold under the trademark of ‘Fiberglas.’ Over time, the term 'fiberglass' became generally used for all glass fiber products. aat:300010457 fireclay (clay) Clay capable of withstanding very high termperatures without fusing or softening; used especially for firebrick and crucibles. aat:300010696 fireproofing tile Tile designed for protecting structural members against fire. aat:300010807 fused silica glass One of the most transparent and heat-resistant of all glasses and is 100% silicon dioxide. aat:300183802 glycerin Colorless, heavy, sweet liquid derived from natural fats and oils. It can be used as a plasticizer in certain media. aat:300011197 gray granite Granite with a mineral composition that results in a gray color and typically fine texture. aat:300011006 gray iron (cast iron) Pig or cast iron containing much graphite. aat:300011496 gray marble Marble with a mineral composition that results in a predominantly gray color. aat:300011655 gray slate Slate that is predominantly gray in color. aat:300011391 graywacke Compact sandstone consisting of quartz, feldspars, and argillaceous maater. aat:300010830 greenhouse glass Low-grade double-strength drawn glass used in the construction of greenhouses; it is slightly wavy so it may cause slight distortion of images viewed through it. Consists largely of glauconite, a greenish granular mineral containing up to 25% iron, with a large percentage of silica and some potash and aluminum, used especially aat:300014343 greensand (soil) as a water softener and as a source of potash. Casting bronze, of from 10 to 15% tin, about 2% zinc, and the balance copper; formerly used for making cannon barrels, and later also for a variety of machine aat:300010960 gunmetal (casting bronze) components and other devices. Also any of several metals or alloys of a dark bluish or purplish gray, used to make firearm barrels and other objects. Any brick molded by hand before firing; a brick mold or stock may be used. Due to the fact that it is less uniform than machine-made brick, it is sometimes preferred for aat:300257776 handmade brick facing. aat:300010605 hard-burned brick A brick that has been burned at high temperature, yielding high compressive strength and durability and low absorption. A metallic black-gray or dark red mineral primarily composed of iron oxide found throughout the world, although the largest source is a sedimentary deposit in the Lake Superior district in North America. It occurs in many physical forms: specular ore (steel gray color, shiny crystals); micaceous hematite (gray, scaly flakes), red ocher aat:300011105 hematite (mineral) (soft, fine-grain, red powder); kidney ore (massive, gray botryoidal form), and pencil ore (gray, fibrous crystals). Because hematite has a high iron content (70%), it is primarily used for smelting iron. It also has been used since ancient times as a red pigment in paints and glazes, for seals, beads, and small carvings since the early 3rd millineum. It is also used as jewelers' rouge for polishing glass and to produce the sparkle in aventurine ceramic glazes. An iron-containing protein pigment occurring in the red blood cells of vertebrates and functioning primarily in the transport of oxygen from the lungs to the tissues of the aat:300192940 hemoglobin body. A conjugated protein linked to a compound of iron and porphyrin. This means it is a metalloprotein containing a heme prosthetic group, either covalently or noncovalently bound to the protein itself. The iron in the heme is capable of undergoing oxidation and reduction. Hemoproteins probably evolved from a primordial aat:300192942 hemoprotein strategy that has been maintained throughout evolution, since it is advantageous to the organism that hemoproteins are responsive to molecules that can bind divalent iron, including but probably not restricted to gaseous molecules such as oxygen, nitric oxide, carbon monoxide, and hydrogen sulfide. Once bound to the prosthetic heme groups of hemoproteins, these gaseous molecules can modulate the activity or function of those hemoproteins in a way that seemingly affords signal transduction. aat:300011382 holystone A block of close-grained sandstone usually used for rubbing down furniture and concrete work. aat:300011749 meager lime Quicklime containing at least 15 percent impurities. aat:300233433 mold-blown glass Glass made by the process of blowing a partly expanded glob of molten glass into a mold. aat:300010658 molded brick Brick molded to a selected shape before firing and subsequently used to make ornamental architectural details. aat:300010934 nonferrous alloy Alloy that does not contain iron. aat:300011014 nonferrous metal Metal that does not have iron as its major ingredient. Glass whose reflectivity has been reduced by the application of coatings; the coatings disperse reflections and increase the light transmission to almost 99 percent. The aat:300010876 nonreflective glass standard nonreflective coating is magnesium fluoride, which gives glass a bluish tint. General term for various earthy materials containing silica, alumina, and iron oxides; often contains compounds of barium or calcium. Occurs in yellowish, brown, or aat:300013951 ocher (inorganic material) reddish colors.Ochers are also used as pigment, colorants in ceramic slips and glazes, added as a reducing agent in luster glazes, and as a filler in linoleum and other products. aat:300263390 paragon (marble) Black marble quarried in Greece and Egypt, used as a touchstone and from the late 16th century in Verona used for painting on. aat:300010557 paving brick A vitrified brick, especially suitable for use in pavements where resistance to abrasion is important. aat:300014482 polyethylene A group of polyolefin polymers derived from ethylene by polymerization by heat and pressure. Prestressed concrete in which tubes, conduits, or channels are inserted in the concrete where steel reinforcement is needed. After curing, reinforcing steel is inserting aat:300010773 post-tensioned prestressed concrete into the tubes, stretched to the appropriate tension, and anchored at the ends. aat:300213129 potassium nitrate A transparent white crystalline compound of the composition KNO3, used in the production of explosives, pyrotechnics, matches, rocket propellants, and fertilizers. Concrete that is cast and cured in other than its final position. For concrete that is deposited in liquid form in the place where it is required to harden as part of a aat:300010771 precast concrete structure, use "cast-in-place concrete." aat:300010772 prestressed concrete Concrete in which effective internal stresses are induced artificially, usually by means of tensioned steel, prior to loading the structure. aat:300010879 prismatic glass Glass in which one surface is smooth, while the other is marked by ridges of prismatic section; illuminates very large internal spaces. aat:300011431 pudding stone Conglomerate rock containing numerous rounded pebbles. aat:300013554 red ocher (pigment) Earth color made from clay or by calcining selected grades of yellow ocher. This type is sometimes called burnt ocher. aat:300014353 sandblast sand Sand employed in a blast of air for cleaning castings, removal of paint, cleaning of metal articles, and for giving a dull, rough finish to glass or metal goods. aat:300310135 seashell The exoskeleton of salt-water mollusks, often used for jewelry or decorative objects. A vegetable oil such as corn or soybean oil, that can be made to dry or form a solid film by chemical treatment, but does not do so on simple exposure to air, as does a aat:300014311 semidrying oil drying oil; not used in artists' oil paint. aat:300011175 semiprecious stone Stone with less commercial value than those classified as precious. Aluminum in an alloy form for the additional strength necessary for construction purposes. Aluminum is lightweight and corrosion-resistant so it does not require aat:300011016 structural aluminum painting, making it an increasingly popular building material. Because aluminum can be extruded, structural shapes can be made economically to meet specific design requirements. Concrete having the characteristic of being resistant to the formation of sulfates due to limiting values of sulfate-ion content in water, the use of grade the use of sulfate aat:300010786 sulfate-resistant concrete resistance portland cement which is low in tricalcium aluminate, or other factors; desirable because this quality protects structural elements from aatack by dissolved sulfates in surrounding water or soil. aat:300014499 sulfone polymer Amorphous high-performance thermoplastic characterized by aryl groups linked by sulfo and ether groups. Orthorhombic mineral of the native element sulfur, having symbol S and atomic number 16. It is found abundantly in volcanic regions, occurring as a brittle crystalline aat:300011156 sulfur (mineral) solid, widely distributed in combination with metals and other substances. It has been used as molten to create small objects and as a gap-filler, for bleaching wood pulp, straw, wool, silk, felt, and linen, for vulcanizing rubber, for making gunpowder, and in the manufacture of sulfa drugs, insecticides, plastic, enamels, and dyes. A cement of clay or other tenacious infusible substance, typically with additions of sulfur, metallic oxides, silica, or carbon; it is used for high-temperature coatings or aat:300010419 sulfur cement coverings and for sealing seams and joints. aat:300011049 terneplate Sheet steel coated with an alloy of 80% lead and 20% tin; widely used for roofing and construction work. aat:300011706 thackstone Sandstone employed as roofing material in the upper Colne valley of England since the thirteenth century. Thin metal foil, of tin, tin alloy, or aluminum, used for various purposes such as damp-proof wrapping for food and tobacco, in food-processing equipment, and in aat:300261762 tinfoil electrical capacitators. aat:300014592 unbleached beeswax Untreated natural beeswax, which is made by bees as a by-product of honey production. For beeswax treated to remove color, use "bleached beeswax." aat:300011783 water vapor The dispersion of water molecules into the air, as produced by evaporation at ambient temperatures rather than boiling. aat:300012994 wood tar Tar obtained by the destructive distillation of wood; used as a preservative.