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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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| JOURNAL OF THE GEMOLOGICAL INSTITUTE OF AMERICA Sri Lanka: Where Tradition and Technology Meet Characteristics...Tomorrow 173 Duncan Pay FEATURE ARTICLES 174 Sri Lanka: Expedition to the Island of Jewels Andrew Lucas...Pedro Padua pg. 175 Offers a firsthand look at Sri Lanka’s mining, cutting, jewelry manufacturing, and...colored stones. 228 Nephrite Jade from Guangxi Province, China Zuowei Yin, Cui Jiang, M. Santosh, Quanli...with flux synthetic ruby overgrowth pg. 243 244 Gem News International Aquamarine with unusually strong |
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| 5 JANUARY 1977 KORNERUPINE CAT'S-EYES FROM SRI LANKA (CEYLON) By H. J. KOREVAAR, F.G.A., Ter Aar, Netherlands...authors (Korevaar), visiting Sri Lanka, bought a parcel of 125 cat's-eyes from a gem dealer in Galle. Although...Weligama gem gravels in the Matara district. Back in Holland, Korevaar contacted the Dutch Gem Laboratory...trip to Sri Lanka in February 1976, the authors noticed a lot of these stones in the Ratnapura Gem Museum...stones offered for sale by people in the street in Ratnapura. It is very likely, therefore, that in the near |
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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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| 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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| 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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| structure Properties of crystals Gem crystals 19 19 20 20 21 22 32 33 3 Gem testing Hardness Gemstones and...Specific gravity 36 37 56 4 Recent developments in gem testing Thermal conductivity Measurement of refractive...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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| 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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| 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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| Fossils, Minerals and Gems, Crytsal Identifier, The Gem and Mineral Collection QUMSPGM Set in Futura Reproduced...provide strength to the unsurprisingly thought that gem weak. Crowns of kings and crystals held supernatural...a more complete and scientific understanding of gem crystals. They can most simply be defined as naturally... Today, many people still hold the belief that gem crystals in their = = wr =i Oo zZ rm wn Gemstone...dissipated. When the conditions are less ‘turbulent’, gem crystals will grow ceaaeos SI out of the solution |
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| Gems: A Historical Perspective Fred L. G r a y 202 Gem Andradite Garnets M.Stoclzton a n d D. V i n c e...FEATURES 232 238 246 249 252 Gem Trade Lab Notes Gemological Abstracts Gem News Book Reviews Suggestions...system contributed t o the demise of the engraved gem seal. During the thousands of years that the seal...most important mark of identification, however, gem engravingreigned as one of his most significant art...engraving process itself, h o w to evaluate an engraved gem, and more recent developments i n the materials and |
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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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| 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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| 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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| Manager Telephone: [800! 4 2 1-7250 x 2 0 1 Editor, Gem Trade Lab Notes C. W. Frver Editor, Gemological Abstracts...Misiorowslzi Contributing Editor, John I. Koivula Editors, Gem News John I. Koivula Robcrt C. Kammerling SUBSCRIPTIONS...Robert E. Kane 47 54 Gem Trade Lab Notes Gems & Gemology Challenge 60 Gem News Book Reviews 62 ...only did the first Sumitomo gem-quality synthetic diamonds appear on the gem marlzet, but De Beers released...information revealing just how far their experiments with gem-quality synthetic diamonds had progressed; one such |
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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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| 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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| BUTTERWORTHS GEM BOOKS GARNET JOHN DROUSE ♦ BUTTERWORTHS ◊ Butterworths Gem Books Edited by Peter...P. J. Darragh Topaz D. B. Hoover Butterworths Gem Books Garnet John D. Rouse Butterworths London...PublicationData Rouse.John D. Gamet.-(Butterworths gem books) 1. Gamet I. Title 553.8'7 QE391.G37 ISBN 0-408-01534-9...Rouse. John D. (John David) Gamet. (Butterworths gem books) Includes bibliographies and index. 1. Gamet...garnets from the perspective of a cutter, dealer and gem enthusiast. The main purpose of this work is not |
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| GEM _ MINERALS^ of Idaho with field trip j& maps by John A.fl£.jkwith Gem Minerals of Idaho, designed...of the gems. Great areas of public land in the Gem to practically unrestricted exploration Only a...other section of the world gem mineral-forming forces than makes Idaho a gem hunter's para- has experienced...Idaho," a fact that dise. L. AND RUTH M. EVANS GEM AND MINERAL COLLECTION COVER PHOTOS FROM THE GLEN...of quartz, it is usually regarded as a distinct gem species. Opal occurs in several varieties of gemological |
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| granulite-facies coronitic gabbro from the Grenville Province, Ontario, Canada, magmatic baddeleyite and zircon...LECHEMINANT the famous gem gravels from Rakwana, District of Kollonnagam, Ceylon (now Sri Lanka ). He donated...identified in coarse gravel from the Balangoda gem district, Ceylon, several years later (Blake and Herbert-Smith...with abundant inclusions) and zoned, euhedral melanite garnet (M). The bright white grain in the NE comer...large baddeleyite stones found in the gem gravels of Sri Lanka (Blake and Herbert-Smith, 1907) may also |
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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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| © 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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| 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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| Corundums Sapphire: Lord Keeper of the Seals in the Gem Kingdom Beryl: Palette of Pastel Colors Emerald:...total beauty. The investigation and explanation of gem colors forms one of the most exciting chapters of...taken place, loose strata were formed, such as gravels, sands, and clays, deposited from water and air...often called placer deposits or alluvial gem gravels. Such gravels are found both in present-day stream beds...Obviously this can only signify that formations of the gem-rich phases of the sial cropped out particularly |
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| their inherently noble traits. The riches of The Gem Kingdom are here revealed in sumptuous illustrations...helped the gem counterfeiter in crafting highly successful facsimiles. In this panorama of the gem kingdom...kingdom the author describes the great gem species, such as diamond, ruby, emerald, and sapphire, as well as...(continued on bac i i : ” that has inspired ; :gem kingdom SPECIAL PHOTOGRAPHY BY S%/JU4-S, 'J...Mark Liebergall Art Production: Doris Mullane The Gem Kingdom, by Paul E. Desautels First Printing All |
