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| inclusions or these cannot be seen because the host gem is too opaque. The brownish opal termed hyalite,...KennethScarratt, Kenneth Scarratt, F.G.A. F.G.A. The Gem Gem Testing Testing Laboratory Laboratory of of Great...Laboratory's name that has changed, firstly from 'The Gem Testing Laboratory of the London Chamber of of Commerce...Commerce and Industry' and then to 'The British Gem Testing Laboratory of the London Chamber ofCommerce...The The Laboratory Laboratory is now known as 'The Gem Testing Laboratory of of Great Britain'.. Britain' |
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| Franks, B.Sc., Ph.D., F.G.A. South Yorkshire & District Branch: J. I. Platts, F.G.A. Examiners: A. J....of natural Tadparadschah ' sapphire found in Sri Lanka. However, a vast production of synthetic flux...'Padparadschah' sapphire Orange sapphire from Sri Lanka from Tanzania COMPARISON OF PHYSICAL PROPERTIES...Tadparadschah ' sapphires and orange sapphires of Sri Lankan and East African origins respectively and...Absorption spectrum of 'Padparaschah ' sapphire from Sri Lanka. (After Schmetzer et al., 1982) 800 I Cr3-+ |
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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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| Australia: Canadian Gemmological Association: Rhodesian Gem and Mineral Society. THE JOURNAL OF GEMMOLOGY A...BRITAIN Vol. X I V N o . 8 O C T O B E R 1975 ON GEM ELBAITE FROM NEWRY, MAINE, U.S.A. By PETE J. DUNN...significant find of gem quality elbaite (lithium tourmaline) was made at the Dunton gem mine, Newry, Maine...facet-grade. Some gem pockets had been found in recent years, but the yield of gem material was small...however, and only serves to give the beautiful red gem material a crackled green coat! The thin outer green |
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| Colombian Emeralds Ron Ringsmd The Elahera Gem Field in Central Sri Lanka Mahinda Gunawardene and Mahinda S....Nassau REGULAR FEATURES Editorial Forum Gem Trade Lab Notes Gem News Gemological Abstracts Book Reviews...LaFayette, Indiana Sallie Morton San lose, CA Editor, Gem Trade Lab Notes C . W. Fryer Editor, Gemological...Jeffrey M. Burbank Contributing Editor and Editor, Gem News John I. Koivula Production Assistant Patricia...COLOMBIAN EMERALDS By Ron Ringsrud The Muzo emerald district, i n Boyacd, Colombia, contains several mines |
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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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| Dimensions in the captions refer to the entire gem or mineral; however, in some cases only a portion...A CHANGING PLANET 11 Vanadinite, San Carlos district, Chihuahua, Mexico * 8 x 4 x 2 cm Mineral Species...can be as valuable as the richly colored stones. Gem cutters bring out the inner beauty of gems by creating...trick with light. Facets allow light to enter the gem; once inside, the light bounces off its other angled...Africa and Canada « 2.00 ct and 3.06 ct leaves the gem, similar to what happens when you pass light through |
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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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| 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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| 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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| 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 |
 | Voudouris, Panagiotis, Mavrogonatos, Constantinos, Graham, Ian, Giuliani, Gaston, Melfos, Vasilios, Karampelas, Stefanos, Karantoni, Vilelmini, Wang, Kandy, Tarantola, Alexandre, Zaw, Khin, Meffre, Sebastien, Klemme, Stephan, Berndt, Jasper, Heidrich, Stefanie, Zaccarini, Federica, Fallick, Anthony, Tsortanidis, Maria, Lampridis, Andreas (2019) Gem Corundum Deposits of Greece: Geology, Mineralogy and Genesis. Minerals, 9 (1) 49 doi:10.3390/min9010049 | Journal (article/letter/editorial) |
| minerals Article Gem Corundum Deposits of Greece: Geology, Mineralogy and Genesis Panagiotis Voudouris... Abstract: Greece contains several gem corundum deposits set within diverse geological settings...–Ti4+ pairs produce blue. Distinction of primary gem quality-rubies and sapphires in magmatic and metamorphic...southern Madagascar, East Africa, South India and Sri Lanka; those related to the Himalayan orogeny mostly...southeast Asia. The use of trace element content of gem corundums, in association with their oxygen isotopic |
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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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| Journal of Gemmology THE GEMMOLOGICAL ASSOCIATION AND GEM TESTING LABORATORY OF GREAT BRITAIN OFFICERS AND... R. Cavey, FGA The Gemmological Association and Gem Testing Laboratory of Great Britain 27 Greville Street...ISSN: 0022-1252 J. Gemm., 1991,22,8 458 THE GEM DIAMOND DIPLOMA GAGTL have brought together the finest...world of diamonds to produce the most comprehensive Gem Diamond home study course available. The course acknowledges...international diamond market and includes every aspect of gem diamond you will ever need to know. Following an |
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| © Tere crree! THE CLEVER GEM BUYER Sclaolalemcveliareln GAVIN LINSELL “She is more precious than...the main reason invariably is that a particular gem means something special to us: they represent a story...perceptions. Now in its second edition, The Clever Gem Buyer brings the reader not only the ‘gemmological’...in an absorbing and entertaining way, The Clever Gem Buyer’s second edition includes even more gemstone...mountain of gemstone rings’ in Thailand's Chanthaburi Province, an international centre for coloured gemstones |
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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...least emphasize the need for eternal vigilance in gem-testing in these tricky times. Synthetic Powellite...Mohs' scale) it is hardly likely to find favour as a gem substitute. T h e stone, weighing only 0-42 carats...which I do not seem to have recorded previously. Gahnite I was glad to purchase recently a transparent green |
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| TREASURES The IN THE SMITHSONIAN Gem Collection Paul E. Desautels ;".'*" - • * « . ^- - ...: »•• * . The Gem Collection TREASURES The IN THE SMITHSONIAN Gem Collection Paul E. Desautels...Paul E Treasures in the Smithsonian: the Gems. gem collection. Smithsonian Institution. Smithsonian...One of the more important gifts to the Smithsonian gem collection in recent years is the 68-carat Victoria-Transvaal...champagne-colored gem was discovered in Africa in 1951. CONTENTS I. II. THE NATIONAL GEM COLLECTION THE |
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| kyewitness CRYSTAL & GEM Apatite Cut topazes Calcite kyewitness CRYSTAL & GEM In association with...of an Indian woman ‘bedecked with jewellery Le GEM OF A CRYSTAL © Most gemstones are natural crystals...two shadow edges, depending on | = | whether the gem is singly or doubly = | refractive, form ona scale...containing fine gemquality crystals are known as gem pockets. This gem pocket CHANGED BY FORCE As a result of...This technique is often used to sort out gem-rich river gravels in areas such as Myanmar (formerly Burma) |
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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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| 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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| supply of cut gems tones. There are a number of gem mining localities in Thailand, many of them in remote...of the fortress of King Rama III (1787-1851). The gem-bearing deposits at Khau Ploi Waen are about six...stones tied to the other end (see Fig. 2). W h e n a gem-bearing stratum is reached each basketful of soil...very low prices. I n quantity, the second m a i n gem production of this area is green sapphire, followed...virtually hedenbergite. M a n y jewellers a n d gem-dealers in Bangkok will inform their customers "These |
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| ing as famous as the renown Mogok Val ley ruby gravels of northern Burma. The potential of finding a ruby...ruby in Cowee Valley attracts thousands of devoted gem seekers as well as interested tourists. The Caler...Mrs. Ruth Shuler and her sons. The ruby bearing gravels of Macon County fill the valley floor of a broad...feet of topsoil may be found two to ten feet of gem bearing gravel. The gravel is dominantly a mixture...In fact, the source of the gem quality rubies and sapphires in these gravels has never been traced. In |
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| retired from his position as Curator in Charge of the gem and mineral collection at the U.S. National Museum...the museum, on collecting expeditions and to major gem and mineral shows where he has often lectured and...sponsored jointly by Friends of Mineralogy, the Tucson Gem and Mineral Society, and the Mineralogical Society...will be held in conjunction with the 38th Tucson Gem and Mineral Show Saturday, February 15, 1992. Pyromorphite...into three b ro ad divisions: (1) Stones (fossils, gem s, “ stones re g u la r,” and “ stones irre g u la |
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| North-West Branch: S. Hill,: F.G.A. South Yorkshire & District Branch: J. L Reynolds, F.G.A. Examiners: E. A...Survey, Exhibition Road, London SW7 2DE, and †British Gem Testing Laboratory, 27 Greville Street, London EC1N...two stones (Fig. 1) were examined at the British Gem Testing Laboratory. Here it was agreed that whilst...stated that it occurred with topaz in the Taplejung District, Dhankuta Zone of eastern Nepal (see Fig. 2)....quality sapphire was also reported from the same district by A. Chikayama at the 19th International Gemmological |
Gem gravels, Ratnapura, Ratnapura District, Sabaragamuwa Province, Sri Lanka