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| invite you to be our guest at Hong Kong Jewellery & Gem Fair September 16th-20th 2019 AWE - Booth 8E03 German...Spinel Pink and Red Gem Spinels in Marble and Placers Spinel from Tajikistan – The Gem That Made Famous...Spinels of Mogok – A Brief Overview Spinels from Sri Lanka 54 The Spinels of Mahenge, Tanzania In Search...Responsibility 94 Book Review Discovering the Gems of Sri Lanka 98 100 108 113 Members 14 Saurabh Bansal Damien...Shirley Xue Li Zhang, Hong Kong E. Gamini Zoysa, Sri Lanka Advisors Jean Claude Michelou, Colombia Ruben |
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| assemblage such as the zeolites from India, or high gem quality such as the rubies from Burma, or some significantly...notable example in this category is the Nuristan District of Afghanistan, which over the past 10 years has...has produced some of the most extraordinary gem minerals ever found. The majority of this volume is based...Saijo, Iyo Province, Ehime Prefecture, Island of Shikoku Ashio Mine, Shimotsuke Province, Tochigi Prefecture...Arakawa Mines, Ugo Province, Akita Prefecture, Honshu The Obira Mine, Bungo Province, Oita Prefecture, |
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| Branch: M. P. Gayton, F.G.A. South Yorkshire & District Branch: 1. R. M. Lewis, F.G.A. Examiners: B. W...many others, I owe all such knowledge of gems and gem materials as I possess—apart, in my case, from such...matters more complicated the actual weights used by gem merchants with their balances were numbered 1000...appeared in the early years of the century are The Gem Cutter's Craft by L. Claremont (London, 1906), which...was my standby when I first started work in the Gem Testing Laboratory, but one had to wait until 1940 |
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| established using a suite of well-characterized Sri Lankan zircon. Band broadening upon increasing corpuscular...Second, we have investigated large, homogeneous, gem-quality zircon samples. These included 13 mildly...radiation-damaged stones from gem gravels in the Ratnapura area, Sri Lanka (U–Pb ages in the range 522–572...concentrations, ages, a-doses and spectroscopic data of the gem samples are listed in Table 2. To identify specific...Lowtemperature photoluminescence-measurements of homogeneous, gem-quality zircon samples were done using a long-distance |
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| Properties of crystals Gem crystals 18 19 19 20 20 21 22 32 33 3 3.1 3.2 3.3 Gem testing Hardness Gemstones...56 4 4.1 4.2 4.3 4.4 4.5 Recent developments in gem testing 59 59 60 61 64 65 Thermal conductivity...understandably and rightly, with the science of gem testing and have covered that area very well. Details...entirely new gem mineral species have been found in the last few years; tanzanite, appearing on the gem market...with no gem potential whatever. It is not likely that many entirely new mineral species with gem application |
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| E. Post, Geologist, Curator-in-Charge, National Gem and Mineral Collection, National Museum of Natural...at www.dk.com CONTENTS INTRODUCTION What is a Gem? 8 How Gems Form 10 Crystals 12 Classifying...Cutting Gems 28 Polishing and Engraving Gems 30 Gem Enhancement 32 Synthetic Gems 34 History and... 214 Index 218 Acknowledgments 223 HOW THE GEM PROFILES WORK main section ; profile information...viene INTRODUCTION ‘ag yet Gay x 2 WHAT IS A GEM? Gems are generally defined as precious or semiprecious |
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| North-West Branch: S. Hill, F.G.A. South Yurkshire & District Branch: J. L Reynolds, F.G.A. Examiners: E. A...Phil., F.G.A.†and V.K. Din, C.Chem., M.R.S.C.†*Gem Testing Laboratory of Great Britain, 27 Greville...with lavas and there is only one major volcanic province - that of Thailand and Kampuchea (Cambodia) -...the Laboratory - 8 Kenneth Scarratt, F.G.A. The Gem Testing Laboratory of Great Britain, 27 Greville...rare gemstone but also in the presentation of any gem material, it is a pleasure to see a diamond fashioned |
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| FEATURE ARTICLES 2 A New Method for Determining Gem Tourmaline Species by LA-ICP-MS Ziyin Sun, Aaron...a simplified but comprehensive classification of gem tourmaline species based on quantitative measurement...Zircon Inclusions in Sapphires from Ratnapura and Balangoda (Sri Lanka) and Implications for Geographic...sapphire • Quarterly Crystal: Orpiment in barite 118 Gem News International Tucson 2019 • Boulder opal mining...Responsibly sourced gemstones • The Chinese and Japanese gem markets • Unusual and vibrant gems • Jeff Hapeman |
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| EDITION AREM, PH.D., FG.A. gem gemologists, 1977, jewelers, and gem collectors, dealers have relied...INTRODUCTION What / Gem? a / Scope of This Book / Is The Nature Gems of GEM SECTION 1 2 GEMSTONES...Rock Classification Gem Scarcity Intrusive Crystal 6 Growth Synthetic Gem 9 / Gemstones SOURCES...dealers are aware of the growing value of exotic gem species; the list of known taaffeites has thus grown...greater monetary reward than are the tists who gem scien- build detection equipment. Inevitably, a |
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| Hays A Prospectors' Guide Map to the Gem Deposits of Sri Lanka C. B. Dissanayuke and M.S . Rupasinghe...Fritsch, and llene Reinitz REGULAR FEATURES Gem Trade Lab Notes Gem News Book Reviews Gemological Abstracts...Hey1 Contributing Editor John I. Koivula Editor, Gem Trade Lab Notes Editor, Gemological Abstracts C....Gems & Gcmology, contact the Association of Japan Gem Trust, Okactumachi Cy Bldg., 5-15-14 Ucno, Taito-ku... Technical Editor Carol M. Stoclcton Editors, Gem News John 1. Koivula Robert C. Kammerling Emmanucl |
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| Sapphires from Sri Lanka Kcirl Scl~metzerand Olaf Medenbach REGULAR FEATURES 112 120 124 131 Gem Trade Lab...Lab Notes Gem News Gemological Abstracts Book Reviews ABOUT THE COVER: The extraordinary play-of-color...Diffraction, one of the less common causes of color in gem materials, is described in this issue in the third...extensive listing of the known origins o f color in gem materials. The opal, from the Ditto 3 Harold &> Collection...pit. Virtually all o f the diamonds recovered are gem quality, although most are relatively small, averaging |
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| Gemesis CVD synthetic diamond New sapphires from Sri Lanka Cultured pearls from Micronesia VOLUME 48 NO...reputation? It’s the most reliable, authentic, dependable gem institute in the world. People know that, especially...Sapphires from Thammannawa, Kataragama Area, Sri Lanka Pannipitiye G. R. Dharmaratne, H. M. Ranjith Premasiri...sapphires, the object of a recent gem rush in southeastern Sri Lanka, possess good transparency and a...research efforts have led to dramatic progress in gem-quality CVD synthesis and post-growth treatment. |
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| E YE WI TNES S HA N D B O O KS GEM STONES The visual guide to more than 130 gemstone varieties...org/details/gemstoneseyewitnOOcall EYEWITNESS HANDBOOKS GEM STONES E YE WI TNESS HANDBOOKS GEMSTONES Cally...varieties are found and fashions change. Over 130 gem species, including some exceptionally rare stones...why the species entries in this its book show the gem rough, natural state, perhaps embedded in still...they can be appreciated by anyone, from the amateur gem-spotter to the enthusiast who enjoys their beauty |
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| No. 8 / 2019 COLUMNS What’s New 679 ABCD Pro-1 Gem Testing Set | D-Imaging Device | Raman Spectroscopy...| Jewelry Journey Podcasts | Gemewizard Gem Color Academy Gem Notes Amethyst from Zimbabwe | Apatite...Fuchsite Phantom Inclusions | Tourmaline from Sri Lanka with Transient Tenebrescence? | Diving for Natural...710–725 of this issue) and therefore does not have a Sri Lankan origin as commonly described for Roman sapphires...Trapiche Ruby from Khoan Thong, Luc Yen Mining District, Northern Vietnam 726 By Isabella Pignatelli |
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| weighing tens of kilograms have been seen at major gem and mineral shows. Downloaded by [University of...during 2003 are the Mineral Section of the Houston Gem and Mineral Society and the Cincinnati Mineral Society...length have been available from the Alto Chapare district, Cochabamba, Bolivia (Petrov 2003). Here it is...Guiv, Kanton Uri (with milarite, datolite, and scheelite). It has also been found at Maglovec Hill, Presov...length have been found in the Bor open pit of this district (Grant and Wilson 2001). Other Russian localities |
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| 1 2 The Geological Sources of Gems Crystalline Gem Materials 3 40 Part II 3 4 5 6 7 8 9 10 11 12 13...The Biological Gem Materials The Fashioning of Gemstones Value-Enhanced Gemstones and Gem Materials 292...library for virtually all sources. Derivations of gem and mineral names are not given; they can be found...not now considered valid or current. While many gem collectors collect mineral specimens too, the text...text for the 1994 edition. In this new edition, the gem testing section has been omitted; this information |
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| if not created, a rapid growth in the hobbies of gem cutting, jewelry making, and mineral collecting....same time people in the jewelry industry and the gem trade have recognized the need for greater technical...description of a great collection, a single gem material, gem cutting, or jewelry mak- ing. In addition...chapter, dealing with the genesis and occurrence of gem minerals, is followed by chapters on the chemical...in their determination. Brief chapters deal with gem inclusions and imperfections, synthesis, imitation |
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| Diamond Industries: 143,145. Acknowledgments: A & S Gem & Mineral Co., Lazare Kaplan International, Goldberg-Weiss...20 21 23 23 24 25 26 Introduction Gem History What Are Gems? Gem Criteria Origin of Gems Marketing of...Brilliancy Specific Gravity Luster and Fluorescence Gem Cutting 31 Gems and Gemstones 32 Diamond 44 Beryl...Irradiation 150 152 153 154 155 156 Gems as Investments Gem Testing Lapidary Hobby Jewelry Metals Popular Styles...is due to their unique properties. The colors of gem materials are among the richest and purest in nature |
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| CVD synthetic diamond | Updated CIBJO Blue Books | Gem laboratory newsletters | New JVC Essential Guides...Photomicrography using a smartphone camera 24 Gem Notes Colourless cat’s-eye apatite | Prismatic Ethiopian...Excursions 69 From the Archives 73 Conferences 78 Gem-A Notices 80 New Media 84 Literature of Interest...Brendan M. Laurs brendan.laurs@gem-a.com Mary A. Burland mary.burland@gem-a.com Executive Editor Editor...Harding Marketing Consultant Ya’akov Almor bizdev@gem-a.com Assistant Editor Michael J. O’Donoghue Associate |
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| Ian Ballour) Contents INTRODUCTION GEM IDENTIFIER Main gem groups Other gemstones Natural glasses...have tried to recognize these fakes. Synthetic gem- and optical properties by which they may be identified...on the scale grains that make them the toughest gem¬ but was in turn scratched by those beneath stones...be un¬ (9) and talc (1). For use in jewellery, gem¬ even, hackly (jagged) or conchoidal (shell - stones...hardness less than 7 are therefore likely common, gem-quality material may be to become scratched with |
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| same time people in the jewelry industry and the gem trade have recognized the need for greater technical...description of a great collection, a single gem material, gem cutting, or jewelry making. In addition many...chapter, dealing with the genesis and occurrence of gem minerals, is followed by chapters on the chemical...in their determination. Brief chapters deal with gem inclusions and imperfections, synthesis, imitation...subject and a gem index to facilitate obtaining con1monly sought information; the name in the gem index is |
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| Penglai, Hainan Island, China W h g Furui 161 A Gem-Quality Iridescent Orthoamphibole from Wyoming R...and fohn I. Koivula REGULAR FEATURES Gem Trade Lab Notes Gem News Gemological Abstracts Book Reviews...Telephone: ( 8 0 0 ) 4 2 1-7250 x 2 0 1 Editor, Gem Trade Lab Notes C, W Fryer Editor, Gemological Abstracts...Misiorowski Contributing Editor, John I. Koivula Editors, Gem News lohn I. Koivula Robert C. Kammerling PRODUCTION...Gems e) Gemology, contact the Association of Japan Gem Trust, Okachin~achi Cy Bldg, 5-15-14 Ucno, Taito-ku |
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| substitute cannot fail to bring further into disrepute a gem material which has been prized from ancient until...control, it has only recently impinged on the world of gem materials in the form of attractively coloured pieces...vigilance in gem-testing in these tricky times. Synthetic Powellite Synthetic scheelite is a fairly well-known...which have been passed on occasion as natural scheelite for high prices to ardent collectors. A cut specimen...powellite, which is a closelyrelated analogue of scheelite, was loaned to m e by the Gemmological Association |
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| North-West Branch: R. Perrett, FGA South Yorkshire & District Branch: G. A. Massie, FGA Examiners: A. J. Allnutt...revealed the stone to be a very unusual assembled gem in which a small chunk of natural Burmese ruby was...Richard W., 1984. Surface repaired rubies a new gem treatment. Journal of Gemmology, 19, 4, 384-6. Scarratt...Gemmological Association has collaborated with the Gem Testing Laboratory of Great Britain to arrange a...Association by Ken Scarratt and will be held at the Gem Testing Laboratory in London.The aim is to give practical |
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| " PP ^ |5& V:.^ jV-. ^: V-. ■• 4* ' N^Sri dr., > A i'-.v ' .1 • , ...,, i ■'>1$ V -...through a stone. This distance factor is useful to gem cutters, who make light coloured stones thicker to...breakthrough, development work continued until a crystal of gem quality was produced in 1970. However, this process...diamonds \ n II \ K A scene from the which are not of gem quality are still being produced and play an important...RUBY Rubies have long been prized as a precious gem¬ The word diamond’ comes from the Greek 'Adamas' |
