A PROPOSED NEW CLASSIFICATION for GEM-QUALITY GARNETS by Carol M
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Structure and Physical Properties of Hydrogrossular Mineral Series
STRUCTURE AND PHYSICAL PROPERTIES OF HYDROGROSSULAR MINERAL SERIES A THESIS IN PHYSICS Presented to the Faculty of the University of Missouri-Kansas City in Partial requirements for the degree MASTER OF SCIENCE By PUJA ADHIKARI M.Sc, Tribhuban University, Kathmandu, Nepal, 2010 Kansas City, Missouri 2015 ©2015 PUJA ADHIKARI ALL RIGHTS RESERVED Structure and physical properties of Hydrogrossular mineral series Puja Adhikari, Candidate for the Master of Science Degree University of Missouri-Kansas City, 2015 ABSTRACT The mineral hydrogrossular series (Ca3Al2(SiO4)3-x(OH) 4x; 0 ≤ x ≤ 3) are important water bearing minerals found in the upper and lower part of the Earth’s mantle. They are vital to the planet’s hydrosphere under different hydrothermal conditions. The composition and structure of this mineral series are important in geoscience and share many commonalities with cement and clay materials. Other than the end members of the series x = 0 (grossular) and x = 3 (katoite) which have a cubic garnet structure, the structure of the series is totally unknown. We used large-scale ab initio modeling to investigate the structures and properties for hydrogrossular series for x = 0, 0.5, 1, 1.5, 2, 2.5, 3. Results indicate that for x > 0 and x < 3, the structures are tetragonal. This shows that there is structural change related to the lowering of overall symmetry associated with the composition of SiO4 tetrahedra and AlO6 octahedra. Total Bond order also explains the reason behind the change in the compressibility of the series. The electronic structure, mechanical and optical properties of the hydrogrossular series are calculated and the results for grossular and katoite are in good agreement with the available experimental data. -
Download PDF About Minerals Sorted by Mineral Name
MINERALS SORTED BY NAME Here is an alphabetical list of minerals discussed on this site. More information on and photographs of these minerals in Kentucky is available in the book “Rocks and Minerals of Kentucky” (Anderson, 1994). APATITE Crystal system: hexagonal. Fracture: conchoidal. Color: red, brown, white. Hardness: 5.0. Luster: opaque or semitransparent. Specific gravity: 3.1. Apatite, also called cellophane, occurs in peridotites in eastern and western Kentucky. A microcrystalline variety of collophane found in northern Woodford County is dark reddish brown, porous, and occurs in phosphatic beds, lenses, and nodules in the Tanglewood Member of the Lexington Limestone. Some fossils in the Tanglewood Member are coated with phosphate. Beds are generally very thin, but occasionally several feet thick. The Woodford County phosphate beds were mined during the early 1900s near Wallace, Ky. BARITE Crystal system: orthorhombic. Cleavage: often in groups of platy or tabular crystals. Color: usually white, but may be light shades of blue, brown, yellow, or red. Hardness: 3.0 to 3.5. Streak: white. Luster: vitreous to pearly. Specific gravity: 4.5. Tenacity: brittle. Uses: in heavy muds in oil-well drilling, to increase brilliance in the glass-making industry, as filler for paper, cosmetics, textiles, linoleum, rubber goods, paints. Barite generally occurs in a white massive variety (often appearing earthy when weathered), although some clear to bluish, bladed barite crystals have been observed in several vein deposits in central Kentucky, and commonly occurs as a solid solution series with celestite where barium and strontium can substitute for each other. Various nodular zones have been observed in Silurian–Devonian rocks in east-central Kentucky. -
A Ground Magnetic Survey of Kimberlite Intrusives in Elliott County, Kentucky
Kentucky Geological Survey James C. Cobb, State Geologist and Director University of Kentucky, Lexington A Ground Magnetic Survey of Kimberlite Intrusives in Elliott County, Kentucky John D. Calandra Thesis Series 2 Series XII, 2000 Kentucky Geological Survey James C. Cobb, State Geologist and Director University of Kentucky, Lexington A Ground Magnetic Survey of Kimberlite Intrusives in Elliott County, Kentucky John D. Calandra On the cover: Photomicrographs of olivine phenoc- rysts: (top) a stressed first-generation olivine pheno- cryst and (bottom) a late-stage olivine phenocryst. Thesis Series 2 Series XII, 2000 i UNIVERSITY OF KENTUCKY Computer and Laboratory Services Section: Charles T. Wethington Jr., President Steven Cordiviola, Head Fitzgerald Bramwell, Vice President for Research and Richard E. Sergeant, Geologist IV Graduate Studies Joseph B. Dixon, Information Technology Manager I Jack Supplee, Director, Administrative Affairs, Research James M. McElhone, Information Systems Technical and Graduate Studies Support Specialist IV Henry E. Francis, Scientist II KENTUCKY GEOLOGICAL SURVEY ADVISORY Karen Cisler, Scientist I BOARD Jason S. Backus, Research Analyst Henry M. Morgan, Chair, Utica Steven R. Mock, Research Analyst Ron D. Gilkerson, Vice Chair, Lexington Tracy Sizemore, Research Analyst William W. Bowdy, Fort Thomas Steve Cawood, Frankfort GEOLOGICAL DIVISION Hugh B. Gabbard, Winchester Coal and Minerals Section: Kenneth Gibson, Madisonville Donald R. Chesnut Jr., Head Mark E. Gormley, Versailles Garland R. Dever Jr., Geologist V Rosanne Kruzich, Louisville Cortland F. Eble, Geologist V W.A. Mossbarger, Lexington Gerald A. Weisenfluh, Geologist V Jacqueline Swigart, Louisville David A. Williams, Geologist V, Henderson office John F. Tate, Bonnyman Stephen F. Greb, Geologist IV David A. -
Washington State Minerals Checklist
Division of Geology and Earth Resources MS 47007; Olympia, WA 98504-7007 Washington State 360-902-1450; 360-902-1785 fax E-mail: [email protected] Website: http://www.dnr.wa.gov/geology Minerals Checklist Note: Mineral names in parentheses are the preferred species names. Compiled by Raymond Lasmanis o Acanthite o Arsenopalladinite o Bustamite o Clinohumite o Enstatite o Harmotome o Actinolite o Arsenopyrite o Bytownite o Clinoptilolite o Epidesmine (Stilbite) o Hastingsite o Adularia o Arsenosulvanite (Plagioclase) o Clinozoisite o Epidote o Hausmannite (Orthoclase) o Arsenpolybasite o Cairngorm (Quartz) o Cobaltite o Epistilbite o Hedenbergite o Aegirine o Astrophyllite o Calamine o Cochromite o Epsomite o Hedleyite o Aenigmatite o Atacamite (Hemimorphite) o Coffinite o Erionite o Hematite o Aeschynite o Atokite o Calaverite o Columbite o Erythrite o Hemimorphite o Agardite-Y o Augite o Calciohilairite (Ferrocolumbite) o Euchroite o Hercynite o Agate (Quartz) o Aurostibite o Calcite, see also o Conichalcite o Euxenite o Hessite o Aguilarite o Austinite Manganocalcite o Connellite o Euxenite-Y o Heulandite o Aktashite o Onyx o Copiapite o o Autunite o Fairchildite Hexahydrite o Alabandite o Caledonite o Copper o o Awaruite o Famatinite Hibschite o Albite o Cancrinite o Copper-zinc o o Axinite group o Fayalite Hillebrandite o Algodonite o Carnelian (Quartz) o Coquandite o o Azurite o Feldspar group Hisingerite o Allanite o Cassiterite o Cordierite o o Barite o Ferberite Hongshiite o Allanite-Ce o Catapleiite o Corrensite o o Bastnäsite -
Geology Club Mineral: Collecting Trip
Geology Club: Mineral Collecting Trip (10 October 2009) Trip Notes by Charles Merguerian STOP 1 – Grossular Garnet Locality, West Redding, Connecticut. [UTM Coordinates: 630.71E / 4575.38N, Bethel quadrangle]. Covering roughly 60 acres of land, this enigmatic massive fine-grained grossularite garnet + diopside rock in West Redding has made many mineral collectors and geologists take notice. Walk up the steep slope east of Simpaug Turnpike to see highly fractured, massive cinnamon-colored grossular garnet rock, part of a 0.6-km wide heart-shaped mass found at the faulted contact between the Stockbridge Marble (OCs) and injected muscovitic schist of the Rowe Schist member (OCr) of the Hartland Formation (Figure 1). According to Rodgers et al. (1985), we are very near Cameron’s Line (red and black line in Figure 1). Figure 1 – Geologic map of the area surrounding Stop 1 showing the Proterozoic gneissic rocks (Yg) and Cambrian Dalton Schist (Cd) to the west, the Stockbridge Marble (OCs), Cameron’s Line (CL in red), the injected schistose rocks of the Rowe Formation (OCr), and an Ordovician granitoid (Og) that may be responsible for this unusual Ca++-enriched skarn deposit. Note the NW-trending high-angle brittle faults that cut the region. (Adapted from Rodgers et al. 1985.) Two knolls at this locality are almost entirely composed of grossularite garnet (var. essonite) and lesser clinopyroxene. Mostly the garnet occurs alone with minor quartz and localized quartz veining has been observed. Chemical analysis of the garnet (SiO2 = 39.10%, CaO = 34.85%, Al2O3 = 19.61%, and total FeO+Fe2O3 = 5.44%), are quite similar to published analyses of grossular garnet, including the phenomenal grossular garnet crystals from Morelos, Mexico. -
Preliminary Investigation of Purple Garnet from a New Deposit in Mozambique
GIT GEMSTONE UPDATE Preliminary Investigation of Purple Garnet from a New Deposit in Mozambique By GIT-Gem testing laboratory 11 May 2016 Introduction In March 2016, a group of Thai gem dealer led by Mr. Pichit Nilprapaporn paid a visit to the GIT and informed us about a new garnet deposit in Mozambique, that was discovered near the western border with Zimbabwe. They also displayed a large parcel of rough and a few cut stones claimed to be the material found in this new deposit (Figure 1). According to the stone’s owner, these garnet specimens were unearthed from an unconsolidated sediment layer, just a few meters below ground surface. This brief report is our preliminary investigation on the interesting vivid purple garnet from the new deposit in Mozambique. Figure 1: Mr. Pichit Nilprapaporn (center), the stone’s owner, showing a large parcel of purple gar- net roughs claimed to be from a new deposit in Mozambique to the GIT director (left). The Gem and Jewelry Institute of Thailand (Public Organization) 140, 140/1-3, 140/5 ITF-Tower Building. 1st - 4th and 6th Floor,Silom Road, Suriyawong, Bangrak, Bangkok 10500 Thailand Tel: +66 2634 4999 Fax: +66 2634 4970; Web: http://www.git.or.th; E-mail: [email protected] 11 May, 2016 Preliminary Investigation of Purple Garnet from a New Deposit in Mozambique 2 Samples and Testing Procedure The stone’s owners donated some specimens (one 6.10 ct oval-facetted stone and 13 rough samples weighing from 3.83 to 9.43 cts) to the GIT Gem Testing Laboratory for studying. -
Mineral Processing
Mineral Processing Foundations of theory and practice of minerallurgy 1st English edition JAN DRZYMALA, C. Eng., Ph.D., D.Sc. Member of the Polish Mineral Processing Society Wroclaw University of Technology 2007 Translation: J. Drzymala, A. Swatek Reviewer: A. Luszczkiewicz Published as supplied by the author ©Copyright by Jan Drzymala, Wroclaw 2007 Computer typesetting: Danuta Szyszka Cover design: Danuta Szyszka Cover photo: Sebastian Bożek Oficyna Wydawnicza Politechniki Wrocławskiej Wybrzeze Wyspianskiego 27 50-370 Wroclaw Any part of this publication can be used in any form by any means provided that the usage is acknowledged by the citation: Drzymala, J., Mineral Processing, Foundations of theory and practice of minerallurgy, Oficyna Wydawnicza PWr., 2007, www.ig.pwr.wroc.pl/minproc ISBN 978-83-7493-362-9 Contents Introduction ....................................................................................................................9 Part I Introduction to mineral processing .....................................................................13 1. From the Big Bang to mineral processing................................................................14 1.1. The formation of matter ...................................................................................14 1.2. Elementary particles.........................................................................................16 1.3. Molecules .........................................................................................................18 1.4. Solids................................................................................................................19 -
Compilation of Reported Sapphire Occurrences in Montana
Report of Investigation 23 Compilation of Reported Sapphire Occurrences in Montana Richard B. Berg 2015 Cover photo by Richard Berg. Sapphires (very pale green and colorless) concentrated by panning. The small red grains are garnets, commonly found with sapphires in western Montana, and the black sand is mainly magnetite. Compilation of Reported Sapphire Occurrences, RI 23 Compilation of Reported Sapphire Occurrences in Montana Richard B. Berg Montana Bureau of Mines and Geology MBMG Report of Investigation 23 2015 i Compilation of Reported Sapphire Occurrences, RI 23 TABLE OF CONTENTS Introduction ............................................................................................................................1 Descriptions of Occurrences ..................................................................................................7 Selected Bibliography of Articles on Montana Sapphires ................................................... 75 General Montana ............................................................................................................75 Yogo ................................................................................................................................ 75 Southwestern Montana Alluvial Deposits........................................................................ 76 Specifi cally Rock Creek sapphire district ........................................................................ 76 Specifi cally Dry Cottonwood Creek deposit and the Butte area .................................... -
Garnet Cigdem Lule, Phd., FGA, GG (GIA)
Market Trends Garnet Cigdem Lule, PhD., FGA, GG (GIA) he Tucson 2015 Gem Show demonstrated that there are considerably more options than just the big three (Truby, sapphire and emerald) for buyers seeking fine quality gemstones. The availability of bigger and higher Figure 1. Tsavorite garnet quality garnets in a range of colors, including color- 6.00cts. Courtesy change was notable. Gem professionals know only too of Mayer & Watt, well that, although red garnets are common, it is no easy photo by Geoffrey task to locate a fine quality rhodolite or spessartine of Watt. 10cts or larger. Dealers with fine red garnets in these sizes reported that the issue isn’t with demand; it is with trying to replace the stone after it’s sold. Similarly, in the Rhodolite 3 carats Commercial Good Fine Extra Fine 2005 4-18 18-35 35-50 50-60 2010 4-18 18-35 35-60 60-70 2015 4-22 30-50 60-95 120-140 Tsavorite 3 carats Commercial Good Fine Extra Fine 2005 225 & up 675-1,000 1,000-1,300 1,300-2,000 2010 240 & up 800-1,400 1,400-1,900 1,900-2,850 2015 240-450 1,150-1,725 2,000-2,400 3,000-3,500 Note. Current price tables have 10 categories but for representation here, categories are combined to show only the four main quality grades. orange category, fine grade mandarin garnets are also their own merit. The per carat price, one of the highest once again achieving greater popularity, and prices are for any garnet, is proof enough of that. -
Exceptional Works of Art 2017 PUSHKIN ANTIQUES – MAYFAIR –
Exceptional works of art 2017 PUSHKIN ANTIQUES – MAYFAIR – At Pushkin Antiques we specialise in unique statement Each item is professionally selected and inspected pieces of antique silver as well as branded luxury items, to ensure we can give our customers a guarantee of stylish interior articles and objects d’art. authenticity and the required peace of mind when buying from us. Since the inception of our company, we’ve been at the forefront of online sales for high end, quality antiques. Our retail gallery is located on the lower floor of the world Our presence on most major platforms has allowed us famous Grays Antiques Centre in the heart of Mayfair. to consistently connect exquisite pieces with the most discerning collectors and interior decorators from all over the world with particular focus on the demands of the markets from the Far East, the Americas, Europe & Russia. www.pushkinantiques.com [email protected] We aim to provide the highest quality in every department: rare hand crafted articles, accurate item descriptions (+44) 02085 544 300 to include the history and provenance of each item, an (+44) 07595 595 079 extensive photography report, as well as a smooth buying process thus facilitating an efficient and pleasant online Shop 111, Lower Ground Floor, Grays Antiques Market. experience. 58 Davies St, London. W1K 5AB, UK. ALEX PUSHKIN OLGA PUSHKINA DUMITRU TIRA Founder & Director Managing Director Photographer Contents 6 ENGLISH SILVER 42 CHINESE SILVER 56 JAPANESE SILVER 66 INDIAN SILVER 78 BURMESE SILVER 86 CONTINENTAL SILVER 100 FRENCH SILVER 108 GERMAN SILVER 118 RUSSIAN SILVER 132 OBJECTS OF VERTU English Silver The style and technique in manufacturing silver during Hester Bateman (1708-1794) was one of the greatest this era (over 100 years) changed radically, reflecting silversmiths operating in this style, she is the most the variations in taste, society, costumes, economic and renowned and appreciated female silversmith of all time. -
Fluorian Garnets from the Host Rocks of the Skaergaard Intrusion: Implications for Metamorphic Fluid Composition
American Mineralogist, Volume 75, pages 859-873,1990 Fluorian garnets from the host rocks of the Skaergaard intrusion: Implications for metamorphic fluid composition CRAIG E. MANNING, * DENNIS K. BIRD Department of Geology, Stanford University, Stanford, California 94305, U.S.A. ABSTRACT Zoned, silica-deficient, calcic garnets containing up to 5 mol% F substitution for 0 formed during contact metamorphism of basalts by the Skaergaard intrusion in East Greenland. Fluorian calcic garnets occur as a retrograde alteration of prograde wollastonite and clinopyroxene that fills vesicles and vugs in lavas 30-70 m from the intrusion. Para- genetically equivalent phases include fluorite, wollastonite, calcic clinopyroxene, prehnite, quartz, and calcite. Electron microprobe analysis shows that the garnets are :::-:93mol% grossular-andradite (grandite) solid solutions and that the F content does not fully com- pensate for the silica deficiency, suggesting the presence of a hydrous component in the garnets. The garnets display discontinuous zoning with respect to Al and Fe, and increases in F, calculated OH, and the Si deficiency with increasing Al concentration are observed. The garnets formed at temperatures between 200 and 420°C based on the coexisting mineral assemblage, and stratigraphic reconstructions indicate pressures of ~ 1 kbar. Assessment of isobaric, isothermal phase relations in the system CaO-A1203-Si02-H20- HF allows estimation of fluid characteristics in equilibrium with fluorian grandite-bearing assemblages. The presence of fluorite, wollastonite, quartz, and calcite with these garnets combined with fluid inclusion data require that the activity (a) of H20 was ~ 1 and that aH.aF was 10-105 to 10-10.0in the coexisting hydrothermal solutions at 200-420 °C and 1 kbar. -
Thomas, R., Rericha, A., Pohl, WL, Davidson, P
Originally published as: Thomas, R., Rericha, A., Pohl, W. L., Davidson, P. (2018): Genetic significance of the 867 cm−1 out-of- plane Raman mode in graphite associated with V-bearing green grossular. - Mineralogy and Petrology, 112, 5, pp. 633—645. DOI: http://doi.org/10.1007/s00710-018-0563-1 1 Genetic significance of the 867 cm-1 out-of-plane Raman mode in graphite associated with V-bearing green grossular Rainer Thomasa Adolf Rerichab Walter L. Pohlc Paul Davidsond Paul Davidson [email protected] 0000-0002-6129-0748 a Helmholtz-Centre Potsdam, German Research Centre for Geoscience – GFZ, Section 4.3. Chemistry and Physics of Earth Materials, Telegrafenberg, D-14473 Potsdam, Germany b Alemannenstr. 4a, D-14612 Falkensee, Germany c Austrian Academy of Sciences, Dr. Ignaz Seipel-Platz 2, 1010 Vienna, Austria d ARC Centre of Excellence in Ore Deposits, University of Tasmania, Hobart 7001, Australia Keywords: Tsavorite Green V-grossular Graphite Raman scattering Fluid and melt inclusions Sulfur 2 Abstract SE Kenya is the world’s largest producer of green vanadium grossular gemstones (tsavorite). Samples from one of the mines near Mwatate, and of occurrences in Tanzania yielded remarkable new insights into the genesis of tsavorite. Graphite is intimately associated with V-grossular and is one of the keys to understanding its origin. In the course of this study we found five different types of graphite. Surprisingly, in one graphite type the “Raman- forbidden” and IR-active 867 cm-1 band was observed. In this communication, we attempt to find an explanation for this unusual phenomenon.