Product Knowledge Training Guide Stone Products Contents

♦ What are the differences in products • • • Travertine • • Onyx •

♦ Applications and uses ♦ Care and maintenance ♦ Glossary of terms ♦ Selling Tips Granite

Granite is an , which was formed by slowly cooling pockets of magma (hot liquid) that was trapped beneath the earth’s surface. It is the result of about 570 million years in the making.

Granite is an intrusive rock – it forms deep underground and consists of mainly feldspar and quartz. Granite is the hardest known material used in commercial and residential applications.

Normally granite is classified in three different groups:

• FINE GRAIN: Fine grain are those in which the feldspar crystals average about 1/16” - 1/8" in diameter.

• MEDIUM GRAIN: Medium grain granites are those in which the feldspar crystals average about 1/4" in diameter.

• COARSE GRAIN: Coarse grain granites are those in which feldspar crystals average 1/2", and greater diameter or several centimeters in maximum dimension. Coarse grain granites may have a lower density.

To Identify Granite: • More granular in appearance that can easily be distinguished • Course and relatively consistent appearance • Dense with minimal pores • Generally minimal variation between tiles or slabs

Common Finishes: • Polished, honed, flamed

Facts: • 6.6 – 8.5 on MOHS hardness scale – very durable • Weather resistant • Crystals can be viewed with the naked eye

Applications and uses: • Granite can be used anywhere: interior/exterior, counters, walls, fireplaces, showers/tubs/vanities, flooring and fountains. • Commercial applications: exterior cladding, steps, heavy traffic areas, sidewalks. Marble

Marble is formed from limestone by heat and pressure in the earth’s crust. These forces cause the limestone to change in texture and makeup.

Marble is a , which means, “changed form”. This process took well over 540 million years. Marble is mostly made up of calcite – a mineral form of calcium carbonate. The purest calcite marble is white. The minerals that result from impurities is what gives marble such a wide variety of colors.

To Identify Marble: • Distinguished veining and crystallization • Large tile to tile variation • Extensive color palette – from white to black

Common Finishes: • Polished, honed, tumbled

Facts: • 2.2 – 5.5 on MOHS hardness scale; relatively soft • Green and black should not be installed in water areas • Not recommended for food service applications • Polish will not sustain if installed in an exterior application

Applications and uses: • Marble can be used on interior applications for walls, fireplaces, shower/tub/vanities and flooring. • Commercial applications: interior walls, statues, heavy traffic flooring (with regular maintenance to maintain polish). Marble

♦ Marble Classification

The Marble Soundness Classifications indicate what method and amount of repair and fabrication are necessary prior to or during installation, as based on standard trade practices. The terms: waxing (1), sticking (2), and filling (3) are common industry terms:

(1) Waxing – Waxing refers to the practice of filling minor surface imperfections such as voids or sand holes with melted shellac, cabinetmaker’s wax or certain polyester compounds. It does not refer to the application of paste wax to make surfaces shinier.

(2) Sticking – Sticking describes the butt edge repair of a broken piece, now generally done with dowels, cements, or epoxies. The pieces are “stuck” together; thus “sticking.”

(3) Filling – Filling refers to the process of filling any surface voids with epoxy, cement, or resin. Filling is not intended to be noticeable to a great degree, perfectly color matched, or “glass” smooth.

(4) Dry Vein - Dry veins are frequently mistakenly thought by consumers to be cracks or unnaturally occurring breaks in the stone. Dry Veins are described when a naturally occurring vein shows a separation between the different materials.

(5) Fissures - Fissures are hairline cracks or grooves and are usually caused by oxidation of the stone. They typically do not affect the soundness of the stone.

Soundness Group A (MIA 11.5.1) - Sound marbles with uniform and favorable working qualities: containing few geological flaws or voids, and subtle and consistent veining. They include completely metamorphosed limestone or dolostone, in which impurities such as clays and silt have reacted chemically with the calcite or dolomite to form other minerals. These stones have uniform working qualities, can be used on the exterior or interior, and do not require any filling or patching. Marble

Soundness Group B (MIA 11.5.2) - Marbles similar in character to Group A, except that all the impurities have not changed into other minerals. Occasional small holes and voids are to be expected, and are characteristics of this group of marbles. The holes or voids are filled by the factory with epoxy, shellac, or polyester resin. Class B may be used on the exterior or interior.

Soundness Group C (MIA 11.5.3) - Marbles with some variations in working qualities. Geological flaws, voids, veins, and lines of separation are common. Many of the impurities have not changed into other minerals, and metamorphosis is not complete. This is the largest and most colorful group of marbles, and also contains significant holes, voids, lines of separation, and structural flaws. It is standard practice to repair these variations by use of reinforcing, liners, sticking together, filling with resin or cement, fabricating corners or missing stone with terrazzo and resin, and doing all other work necessary to hold the stone together to yield a finished product that is usable for architectural purposes. On completion, most repairs are visible and apparent, with a difference in light reflection. They contain mesh, resin, epoxy, or fiberglass backing. With few exceptions, these marbles are not suitable for exterior installation.

Soundness Group D (MIA 11.5.4) - Marbles similar to the preceding group, but con- taining a larger proportion of natural faults, maximum variations in working qualities, and requiring more of the same methods of finishing. Few stones carry this designation at this time; it is reserved for very laborious Group C stones.

♦ Special Notes

Green Marbles Green marbles are not recommended for wet areas of your home, and they are not recommended to be used with water based adhesives during installation. Because of the unique mineral content in these marbles, the tiles will absorb the water and may have a tendency to curl or warp. With this dynamic in mind, the only way to prevent issues is to install it properly with a non-water based material such as epoxy.

Resin Back Marbles The resin backings are designed to provide rigidity and to stabilize some of the more fragile stone types used on floors. These backings can be composed of polyester, urethane or epoxy. Some backings can include fiber-mesh scrims. The best results come from installing resin-backed stones with an epoxy-based adhesive. Slate

Slate is a metamorphic rock. Most slate is formed below the earth’s surface by changes in the makeup and appearance of shale, which is a sedimentary rock. Shale consists of clay and fine particles of quartz.

Heat from deep in the earth changes some of the clay in shale into mica and chlorite. Slate results when pressure created chiefly by mountain-forming movements in the earth’s crust squeezes the mica and other minerals into parallel layers.

To Identify Slate: • Common colors: from grays and blacks to rusts and greens (many are multi-colored) • Large tile to tile color and surface variation • Slate has a layered appearance

Common Finishes: • Natural cleft, gauged, ungauged, tumbled, honed, polished

Facts: • 6.0 on MOHS hardness scale; very durable • Shaling (pieces falling off face) is common within the first 6 months of installation • Made up of mostly clay and shale (silt and clay); very dense

Applications and uses: • Slate can be used in interior and exterior applications: walls, fireplaces, showers/tubs/vanities, flooring, fountains and backsplashes. • Commercial applications: roofing, exterior/interior cladding, trim accents and some flooring applications. Slate

♦ Slate - Interior Applications

Characteristics In the industry there are various stones that go by the name “slate”, some of which include quartzite, shale, and schist. Although similar in appearance, these rocks vary in their formation, mineral content, and their advised applications.

Most varieties of slate represent a wide spectrum of colors. Due to this high variation, no two tiles are alike and the stone will vary from batch to batch. It is impractical to attempt hand selecting the colors. Tiles that were cut out of the same block may consist of solid colors from opposite ends of the spectrum and may contain infinite combinations of movement.

Flaking Slate is a foliated rock. The layers will have a tendency to flake post installation as the stone settles. Not only is there potential for additional colors of the stone to be exposed as a layer cleaves off, but the texture may also change as a result. This is not a defect of the stone, and eventually the flaking will stop. When used in wet applications where drains are present, it is recommended that a fine net be placed in the drain to catch the pieces of rock during the settling process.

Rust It is not uncommon to see rust appear on slate as a result of iron and other minerals within the stone oxidizing from moisture. Oxidation is an inherent characteristic of many stones and must not be left untreated, as it may cause the stone to become brittle over time. Proper use of sealers as well as a water proofing membrane on the substrate will prevent this from happening.

Absorption Slate’s absorption rate can be as low as .2%, which is often seen in slate roof tiles. Some variations; however, can be as absorbent as 10%. The absorption rate will vary between different types of slate. Even with a low absorption rate, water may still penetrate the surface and compromise the stones’ stability. Water will find its way through any crack or crevice which potentially will cause the stone to swell. This type of swelling in slates will also make them brittle and may even weaken the tile’s bond to the substrate. It is highly recommended that stones be sealed to prevent any type of water damage. These chemical sealers may need to be reapplied based on the manufacturer’s instructions to ensure the longevity of your tile. Slate

♦ Slate - Exterior Applications

Characteristics Slate is a metamorphic, foliated rock comprised of various layers of mud, mineral flakes and shale, whereas quartzite is non-foliated and is typically a metamorphosis of . Although at first glance these stones look similar, they carry different characteristics and attributes that are critical to their applications.

The formation of these rocks is significant for a number of reasons. By understanding that slate is foliated, the layers will have a tendency to flake post installation as the stone settles. Not only is there potential for additional colors of the stone to be exposed as a layer cleaves off, but as a result the texture may also change. This is not a defect of the stone, and eventually the flaking will stop. Quartzite on the other hand will be more consistent in color and texture since it is not formed in the same type of layers and will not go through the same settling process post installation.

Freeze / Thaw Climates and Weathering Although slates are rated for exterior use, not all of them are freeze/thaw rated. In freeze/ thaw climates, when water penetrates the surface of a stone and freezes over, there is a risk of the tile shattering. When water freezes, it expands by approximately 9%. As this expansion is resisted, the pressure exerted can be up to 150 tons per square foot. This type of pressure is sufficient to split even the strongest rocks. Because slate is a foliated stone, the splitting will be unpredictable, and will likely break apart in random segments.

Installation Aside from slate’s natural porous characteristics, other factors affect water retention in the stone. If slate is not installed using the proper water proofing membranes in an exterior application, water will find its way through any cracks or crevices which potentially will cause the stone to swell. This type of swelling in slate will also make them brittle and may even weaken the tile’s bond to the substrate. Flaking can be magnified as a result of such swelling.

Appropriate measures must be taken to install a stone of this nature in any exterior application. There are various sealers on the market as well as waterproofing membranes that will offset any negative effects the weather may have on slate. These chemical sealers may need to be reapplied based on the manufacturer’s instructions to ensure the longevity of the tile. Limestone

Limestone is comprised chiefly of calcite, a mineral form of calcium carbonate. It is also sometimes referred to as a ‘young’ marble. Limestone was formed over many years (320 million) at the bottom of oceans and lakes, which designates it as a sedimentary stone. consist of an accumulation of shells, bones, and other calcium rich goods.

Limestone is divided into three sub-classifications that describe their densities in approximate ranges, as follows:

• LOW DENSITY - Limestone having a density ranging from 110 through 135/lb/ft3 (1760 through 2160 kg/m3). • MEDIUM DENSITY - Limestone having a density greater that 135 and not greater than 160 lb/ft3 (2160 through 2560 kg/m3). • HIGH DENSITY - Limestone having a density greater than 160 lb/ft3 (2560 kg/m3).

Limestone contains a number of distinguishable natural characteristics, including calcite streaks or spots, fossils or shell formations, pit holes, reedy formations, open texture streaks, honeycomb formations, iron spots, travertine -like formations and grain formation changes. One or a combination of these characteristics will affect the texture.

To Identify Limestone: • Common colors – beige, gray, white – fairly neutral in color • Fairly consistent tile to tile variation • Tight-grained appearance

Common Finishes: • Honed, polished, sandblasted

Facts: • 3.0 – 4.0 on MOHS hardness scale – very soft • Limestone makes an excellent building stone – it can be carved easily • If shell fossils are still visible (although polished), it is considered a limestone not a marble

Applications and uses: • Limestone can be used in interior and some exterior applications: walls, fireplaces, showers/tubs/vanities, flooring. • Commercial applications: interior and some exterior cladding, flooring. Travertine

Travertine is limestone that has been evolved and formed over a longer period of time. The product is porous with many visible holes. Travertine is available in colors ranging from ivory to golden brown. The holes and cavities may be filled with matching Portland cement, colored epoxy, or polyester resins. Travertine is a sedimentary, calciferous stone formed in hot springs. Typically, hot water passes through limestone beds, taking the calcium from the limestone into suspension and bringing that solution to the surface. The water then evaporates and leaves the calcium crystals in layers on the surface.

To Identify Travertine: • Holes or cavities visible in stone – filled or unfilled • Produced with either a “vein cut” (horizontal veins) or a “cross cut” (flowery pattern) • Quarried near hot springs

Common Finishes: • Honed, polished, tumbled, filled, unfilled

Facts: • 3.0 – 5.5 on MOHS hardness scale – moderate strength • The Coliseum in Rome is made of travertine • Unfilled gives a rustic appearance while filled gives a more formal look

Applications and uses: • Travertine can be used in interior and exterior applications: walls, fireplaces, showers/tubs/vanities, flooring, and backsplashes. • Commercial applications: interior and some exterior cladding, flooring. Travertine

♦ Special Notes

Within the first 12 - 18 months of installation of a filled and honed travertine floor, it is normal to expect 5 – 10% of the floor to experience exposure of new holes, particularly in high traffic areas.

This occurs due to the nature of travertine itself as it is a capillary filled stone. When the tiles go along the filling line, the machine will fill all the visible holes, pits and fissures on the surface prior to polishing. During installation and the settling process post installation, it is common for foot traffic, furniture, etc. to expose these voids or loosen the fillers. This will be visible in high traffic areas and is normal and expected with all filled stones.

To remedy this issue, it is best to wait at least 12 months for most of the shallow pores to expose themselves. At this time, clean out any loose debris in the exposed area. Do not dig or stick sharp instruments into the hole, as it will exaggerate the problem and possibly open up additional holes than would not occur normally with natural foot traffic. Make sure the area around the void is repaired and sealed well as to not allow any new grout to adhere to the stone’s surface. Fill the holes with regular sanded or epoxy grout (whatever color is deemed appropriate to match the stone). After this application is completed, make sure these newly grouted areas are sealed with any regular non-solvent based stone sealer. Onyx

Onyx is a translucent stone with a layered appearance.

Onyx is similar to travertine, as it is formed as a result of cold solutions of carbonated water dissolving existing stone and re-depositing it into a new stone. The term “onyx” to designate onyx marble is a misnomer. True onyx (silicon dioxide) is a semi-precious stone.

To Identify Granite: • Translucent in appearance • Common colors – jade green, warm honey tones, and reds • Very large tile to tile variation

Common Finishes: • Polished, tumbled

Facts: • Very soft and brittle • Scratches easily • Beautiful when lighting is installed behind the stone

Applications and uses: • Onyx can be installed in bathrooms and low traffic areas. • Commercial applications: bar tops, vertical cladding. General Information

The Moh’s hardness scale was created to measure the hardness of minerals. The scale starts with the softest mineral (talc), and progresses to the hardest (diamond). The only thing that can scratch a diamond is itself.

Hardness and specific gravity are two of the major characteristics of rocks. Hardness of a rock or mineral is defined by its resistance to scratching and may be described relative to a standard scale of 10 minerals known as the Mohs Scale.

F. Mohs, an Austrian mineralogist, developed this scale in 1822. Specific gravity is the number of times heavier a gemstone of any volume is than an equal volume of water. In other words, it is the ratio of the density of the gemstone to the density of water. General Information

Variation in veining, fissures, pits, texture, color, and shade is an inherent characteristic of all natural stones. These variations are to be expected from tile to tile as well as from lot to lot, depending on the type of stone that is selected.

Some species and colors are more consistent than others and will range from V0-V5 shade variation. Hand selecting colors is not practical for natural stones, although range samples can be requested to represent the current lot prior to purchasing.

Preventive Measures against Shade Variation It is important to inspect all tiles prior to installation. Subtle variations between a darker and lighter shade can usually be hidden when the darker shade is put around the perimeter of the room and the lighter shades are used in the middle of the room to avoid creating unwanted contrasts or patterns.

During product inspection, tiles that are questionable or unusable should be set aside. It is also important to calculate proper overage when purchasing (usually 20%), as an allowance for waste from cuts and color variation. Professional installers will pull from multiple boxes to help blend the natural variation between tiles.

Grades of Marble Marbles and other natural stones are categorized by soundness classifications: A-D. Some C and D stones are manufactured with resin reinforced mesh backing, holes are filled with cement or epoxy and rods are used for stability. Veining and coloring can be inconsistent. Chipped edges and corners are repaired with epoxy.

Some species of stone have more inconsistencies than others; however this is not a defect of the stone. It is industry standard as long as it is graded correctly. General Information

Sealing Granite As a general rule, it is important to seal all natural stones, even granites. However, the only stone that typically goes unsealed is black granite. When used as countertops or in wet applications, sealed black granites are known to show water marks and rings when exposed to moisture or acids for extended periods of time. These watermarks or “etching” can be caused by a number of factors: The most common being a reaction of the sealer being exposed to water for prolonged periods. Another reason may be a reaction of the mineral on the surface of the stone to acids. In both cases, it is best to contact the sealer manufacturer for recommendations on cleaning these spots.

Slate Exteriors Most slates are not rated for exteriors, wet applications, or freeze / thaw climates. Slates can swell in wet applications, become muddy, become brittle, rust, flake, and fall apart. It is important to know where the slate is being installed prior to recommending it for a particular application. Quartzite, although it looks like slate, is a completely different rock and it can be used in both wet applications and exterior freeze thaw climates.

Epoxy Thin-sets It is important to use epoxy based, solid setting adhesives and grouts when installing mesh, resin, epoxy, or fiberglass backed stones to ensure proper adhesion. Stones requiring epoxy thinsets, even if they are not mesh-backed are: green marbles, black marbles, and some varieties of . These stones typically warp or can acquire efflorescence from moisture in a standard mortar / thin-set.

Lippage Lippage is caused by a number of factors: Uneven subfloors, not back buttering large tiles, grout joints that are too narrow, natural light source making standard variances more noticeable, etc. The first things inspectors will look for on a lippage claim is a soft joint around the perimeter of the application, variances in the tile accounted for with the proper grout joint widths, and proper offset percentages if a brick joint pattern was used.

Recommended Off-Set for Brick Joint Patterns A 33% maximum off-set and proper grout joint width is recommended to prevent the appearance of lippage.

A 50% off-set on large format square and rectangular tiles is not recommended, due to standard manufacturing tolerances. Stone Maintenance & Care

All natural stone should been maintained properly. All finishes of stone – honed, polished or tumbled, look beautiful and are very durable when protected and maintained. Sealing all natural stone is highly recommended.

It is suggested that a breathable, penetrating sealer is applied. Aqua Mix as well Miracle Sealants provide different types of high quality penetrating sealers

Tips: • Sweep or vacuum floors regularly • Wash with clear water occasionally – if soap is used, it must be PH balanced! • Never use vinegar on natural stone • Never use any cleaners that contain ACID • Protect stone from sand and grit – use door mats • Use a rag (string) mop verses a sponge mop – dirt gets pushed into the grout joints with a sponge mop • Tend to spills quickly. Good sealers provide a window of a few seconds for clean up. Sealers do not prevent 100% of damage due to spills.

Efflorescence, Rust, and Moisture Sensitive Stones All stones are porous to varying degrees. Efflorescence and rust can be a common occurrence in natural stones when they are exposed to moisture. It is important to identify the source of the problem before cleaning or replacing the stone, as these occurrences can be installation related.

Efflorescence is a concentration of soluble salt trapped in the stone that will appear cloudy and white. It is common in hot climates where the water escapes from the stone quickly, leaving a trace of salt closer to the surface. Rust will also appear when the metal minerals of certain types of stone react with moisture. Both rust and efflorescence can be cleaned using water and a medium bristle brush. Where the deposits have been present for a while, a light muriatic acid mix can be used to clean the surface of the stone.

It is imperative that the stone be properly sealed after cleaning. Proper water proofing membranes are required where product is exposed to weathering or is in direct contact with water. The use of a sealer is highly recommended to protect the surface of the stone. Stone Maintenance & Care

♦ Common Questions

Why is Granite preferred for kitchen / bar countertops? Countertops in kitchens and bar areas are often exposed to acidic substances such as lemon, vinegar, alcohol, tomato sauce, etc. Knives, dishes, pots and pans, and other implements may cause scratching of softer materials. Granite is the hardest and densest of all natural stones. The feldspar content keeps it water resistant, and the silicates it contains won’t react with acid. These properties help Granite resist staining and retain its fine luster over a longer period of time than ceramic tiles or other stones. Although Marble is commonly requested for countertops in bars and kitchens, marble’s high carbonate content makes it vulnerable to acidic substances.

Why are Limestone and Travertine preferred for family or living rooms? The family or living room in a home is a place for peace and relaxation, and the soft, muted tones and textures of limestone or travertine are the perfect touch. Available in shades of beige, tan, yellow and gold and processed with a tumbled or antiqued texture, limestone complements all types of furniture and upholstery.

Why is Marble preferred for bathrooms and fireplaces? Homeowners often enjoy bathrooms with bold colors and smooth, flowing patterns. Marble is the perfect choice for this application due to its wide spectrum of available colors. It also lends itself well to carved patterns and details, creating both traditional and artistic designs. While kitchen countertops are often exposed to acidic substances, bathroom countertops are more likely to be exposed to alkaline products, which do not react with Marble.

Why is Slate preferred for patios or atriums? The earth tones and rustic look of slate create a comfortable, natural look that is right at home with exterior landscaping and interior garden designs. Slate is naturally slip resistant, even when wet, and is much less likely to show dust and dirt than polished granite or marble. It’s also relatively low priced, which makes it a great choice for large, informal areas.

Where do natural stones come from? Natural stones are quarried directly from the earth’s crust, and every piece is unique. The only processing they need is shaping into various forms, sizes and finishes. Stone Maintenance & Care

Why are most natural stones imported? Sources of natural stone with desirable qualities are found all over the world in many different locations. Some sources are preferable to others, due to the stones’ appearance, hardness, and other qualities. Therefore, stone may be quarried in China, India, Africa, South America, Europe and North America. Cost of processing is also a factor. Since natural stone has been used as a building material for thousands of years in many locations overseas, those areas have a long-established system for quarrying and processing these stones which is efficient and economical.

What is the quality difference in stone from different countries? Natural stone from different areas contains a varied mix of mineral deposits and rock formations. For example, the mineral Mica may be found more frequently in some areas, which means that the rock from that location will contain bigger shiny crystals than we would find in places where less Mica is found. Some countries quarry more limestone than granite. Therefore, stone from certain places may be better suited for one application than another. Natural stone qualities and characteristics differ due to geological formations, not geographical boundaries.

Why some stones could not be used for exterior applications? Some types of stone are better suited for interior applications than exterior because they are not able to withstand harsh weather extremes and may crack, crumble, or fade. Also, stones with naturally slip-resistant surfaces are better for outdoor walkways or patios than those with smooth, polished surfaces. Some multicolored slates bleed color upon contact with water.

How to install resin-backed stone products? In some cases there may be a waxy, slick backing covering the mesh on the back (setting) side of the stone. This is common with thin stones or those with a lot of veining and / or fissures. While the stone without the resin backing makes for a straightforward installation, some varieties of stones are too thin and / or fragile to withstand the rigors of handling prior to being installed. Stone Maintenance & Care

♦ Types of Resins

Knowing the type of resin backing on the stone can help to determine if the adhesive mortar being used is appropriate. These backings can be composed of polyester, urethane, or epoxy. Some backings can include fiber-mesh scrims. Others may include another thinly cut stone laminated to the back of another stone. The backings are designed to provide rigidity and to stabilize some of the more fragile stone types used on floors.

Some stone manufacturers will broadcast sharp sand or other aggregate into the resin to facilitate better mechanical grip or adhesion to the mortar. When this is the case, a latex-modified mortar may be used. The type of resin used can also influence the adhesive that is used. Keep in mind that there may be count- less types and varying quality of resins used on the backs of these stones. Despite this fact, there are three main family types that these resins fall into: polyester, epoxy and urethane.

The polyester types can be somewhat problematic. They are the most common, since they are the most inexpensive type. Polyester resin is generally a cold applied material that is poured or rolled onto the back of the stone. As it hardens, a waxy film develops on the surface of the resin. This very slick material presents a daunting problem for most latex thin-set mortars. Therefore, it is best to use an epoxy adhesive for these types of resin backings.

Epoxy resin meshes are of better quality than polyester meshes, however latex thin-set mortars will have a hard time bonding to epoxy resins. The epoxy resins are generally a two-part product made up of one part hardener and one part resin. This material is generally cold applied, but relies on chemical reaction to cure out and harden. Epoxy adhesives are the preferred choice to install these stones.

Urethane backings are probably the type that is least commonly used. Epoxy adhesives are also be the best choice to use for urethane meshes.

An interesting fact is that there are currently no standards to determine what the minimum bond strength of the resin backing to the actual stone should be. This leaves an installer with the unfortunate task of trying to determine if the stone and backing are suitable.

There is another area of concern when it comes to installing these stones that should be considered. It is important to validate the bond strength of the resin mesh to the back of the stone. If it is easy to remove this backing, it will be of no use to install the stone, as it is a project failure waiting to happen. Stone - Glossary of Terms

Breathing: The ability of a stone to expand and contract as well as to allow evaporation of moisture.

Chip: A small piece of a stone that can be replaced (or repaired) with epoxy resin or filled with crushed chips and epoxy.

Density: The closeness of the particles in the material. Granite, for Instance is more dense than marble; therefore, it is harder, heavier, and less porous.

Etch: Also known as acid burn. The condition whereby acid or strong alkaline has dissolved a portion of the stone.

Epoxy: A two-part resin glue used for joining and filling stone.

Fissures: Natural hairline fractures. When the stone was going through the metamorphic changes with heat and pressure there were veins of silt and dirt collected that have since disappeared.

Flamed Finish: Flamed finish is used on granite. The surface is flamed with acetylene torch until the weak part of the stone separates in an irregular pattern. The result is non-reflective, textured, durable and slip-resistant surface.

Fleuri Cut: Also known as cross-cut. Typically used with travertine. It reveals a flower-like pattern. A block of stone is cut on the bias to create a new surface look.

Honed Finish: This finish creates a smooth, but not polished, surface. The same polishing stone that can create a high gloss are used but the process is stopped prior to a shine. Stone - Glossary of Terms

Grout: Grout consists of cement, hardeners, and colors or epoxy and colors. It is used in a fluid state to fill the space between tiles or joints and allowed to harden. Grout acts like a shock absorber between tiles or stones. A cement grout comes in two versions – sanded for grout joints over 1/8” and unsanded for anything else.

Igneous: Granite is an igneous rock which means it was once molten and formed as it cooled deep within the earth.

Intrusive: Granite is an intrusive rock – found deep within the mantle of a volcano; whereas, lava is an extrusive rock – spewed forth from the volcano.

Polish: The shiny surface of a stone. The polishing process and special buffing compounds achieve this.

Porosity: Refers to the amount and size or the pores in a stone. Travertine is extremely porous. Granite is not very porous.

Slab: A natural stone slab is preliminary used for kitchen counters, vanities and cladding. The common size is 6’x8’ with rough edges. It is then fabricated to a desired size.

Stone Tile: Natural stone that has been cut down to typical; 12”x12” or larger 16”x16”, 18”x18”, 24”x24” or a modular size.

Spalling: Small chunks that break away from the face of a stone. Stone - Selling Tips

• Natural stone is a product of nature and is unique, beautiful, and adds personality to the environment and is not meant to be uniform, consistent or flawless.

• The price of a natural stone product is not always directly related to the perceived quality. - Price can be impacted by availability and or exchange rates due to the country of origin.

• Don’t confuse quality with the stone’s inherent characteristics. - Voids, fissures and fill are common in all natural stone products.

• Natural stone has variations. Viewing or sampling one piece of stone may not adequately represent the full range or beauty of a product.

• A polished stone is not a sealed stone – the polished finish is more aesthetic than functional. It is recommended to seal all stone products after installation.

• Green marbles – are not recommended for wet areas because, like wood, they absorb water and will curl and warp. For other areas we recommend a water-free epoxy to set the product in.

• Black marbles – they also respond to water by spalling at the vein and therefore should not be installed in wet areas. For other areas we recommend a water-free epoxy to set the product in.