 | Giuliani, Gaston, Fallick, Anthony E., Boyce, Adrian J., Pardieu, Vincent, Pham, Van Long (2017) Pink and Red Spinels In Marble: Trace Elements, Oxygen Isotopes, and Sources. The Canadian Mineralogist, 55 (4) 743-761 doi:10.3749/canmin.1700009 | Journal (article/letter/editorial) |
| of the main productive and historical sources of gem spinel. Three consistent sets of d18O values were...study shows that it is possible to discriminate gem spinels hosted by marbles from different geographic...oxygen isotopes, geographic origin. INTRODUCTION Gem spinel belongs to the aluminous spinel subgroup A2þB3þ2O4...Yen area, Vietnam. (E) Spinel (Spl) in forsterite (forsterite, Fo þ lizardite, Lz) skarn rock associated...Pardieu/GIA; (E) E. Gaillou/ENSMP. Badakshan Province in Afghanistan (Spencer 1937). In Roman times |
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| THE ORIGIN OF GEMSTONES TISSA MUNASINGHE OF SRI LANKA AND C. B. DISSANAYAKE Department of Geology...Geology, University of Peradeniya,Peradeniya,Sri Lanka Sri Lanka is well known throughout the world for its...topaz, and zircon. Largescale gem mining is confined mainly to the Ratnapura and Elahera areas (Fig. 1)...1). In most local- ities gem minerals are recovered from residual, alluvial, and eluvial depositsthough...common (Dahanayake et al., 1980). The gem-bearing beds in the Ratnapura area are mostly alluvial in origin |
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| Concentrated by Surface Waters: 1 5 The Gem Gravels of Sri Lanka 2. Gemstones Formed from Surface Water:...Gemstones of Igneous-Hydrothermal Origin 3. Hydrothermal Gem Deposits: 35 39 The Emerald Deposits of Colombia...Colombia 4. Gemstones Formed in Pegmatites: 57 Gem Pegmatites of Minas Gerais, Brazil 5. Gemstones Formed...Gemstones Formed at Great Depths 8. Mantle Thrust Sheet Gem Deposits: 115 119 The Zabargad Island, Egypt, Peridot... Western Australia Index 141 FOREWORD Each gem deposit-whether of primary origin in the parent rocks; |
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| Concentrated by Surface Waters: 1 5 The Gem Gravels of Sri Lanka 2. Gemstones Formed from Surface Water:...Gemstones of Igneous-Hydrothermal Origin 3. Hydrothermal Gem Deposits: 35 39 The Emerald Deposits of Colombia...Colombia 4. Gemstones Formed in Pegmatites: 57 Gem Pegmatites of Minas Gerais, Brazil 5. Gemstones Formed...Gemstones Formed at Great Depths 8. Mantle Thrust Sheet Gem Deposits: 115 119 The Zabargad Island, Egypt, Peridot... Western Australia Index 141 FOREWORD Each gem deposit-whether of primary origin in the parent rocks; |
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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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| 2 TABLE OF CONTENTS FEATURE ARTICLES 62 Sri Lanka: The Gem Island Peter C. Zwnan The Identification...Illumination: A Controllable System of Lighting for Gem Microscopy John I. Koivula 8 7 Radioactive Irradiated...Greenland Aage Jensen and Ole V. Petersen Carving Gem-Quality Opal Theodore Grussing Two Notable Color-Change...REGULAR FEATURES Gem Trade Lab Notes Editorial Forum Gemological Abstracts Book Reviews Gem News , A B O...a n y fine gemstones found on the island o f Sri Lanka, the subject of Peter Zwaan's article i n this |
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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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| extensive native plantations in the Northern Province, especially in the Jaffna Peninsula and the outlying...and December, the rainy season of the Northern Province. Sugar or “jaggery ” is prepared from sweet toddy...stone inthe Western Province, or of tamarind wood in the North-Central Province; in this a heavy pesile...to one family of ivory workers in the Kegalla District. The little figures of the last King of Kandy...Chief Priest are said to be contemporary portraits. Sri Wikrama Raja Sinha was the last king of the Suluwansa |
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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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| 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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| 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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| of gems found in alluvial deposits of the Ratnapura district now runs to several million pounds, it is...fortunate in discovering a new corundum locality where gem-quality sapphire has developed along the contact...190 feet. Coarsegrained dolomitic marble with forsterite, diopside, and phlogopite, accompanied by accessory...detail of habit to the crystals recovered from gem gravels some 20 miles to the south-west. A high proportion...proportion of these sapphires are clear and of good gem quality, but a few are flawed by a rhombohedral parting |
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| reputation? It’s the most reliable, authentic, dependable gem institute in the world. People know that, especially...Sapphire from the Tan Huong–Truc Lau Area, Yen Bai Province, Northern Vietnam Nguyen Ngoc Khoi, Chakkaphan...Nhung Although not as well known as the Luc Yen district, this area is an important source of ruby and...Green sapphires with different chromophores 234 Gem News International Greenish brown diamonds with color...and zircon from Ethiopia • Sapphire mining in Sri Lanka • Green cat’s-eye spodumene from Brazil • Color-zoned |
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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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| 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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| 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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| provides a comprehensive examination of gems and gem materials including discussion of their properties...and popularity in different cultures. The Museum's gem collection, itself the stuff of legends, is described...factors important in determining the quality of each gem and spells out the possible confusions in gemstone...TO THOSE WHO HAVE HELPED CREATE THE MINERAL AND GEM COLLECTIONS. Those whose donations are featured...Tourmaline PAGE 88 18 Zircon& What1a Rridot Gem? PAGE PAGE 22 Corundum Diamond PAGE PAGE 44 |
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| Trinchillo Sapat Gali, Mansehra District, Khyber Pakhtunkhwa Province, Pakistan ........................com Aquamarine & Quartz | Nyet-Bruk, Skardu District, Pakistan | 15 cm orders@crystalclassics.co...trip to Pakistan I was on the hunt for a different gem mineral: tourmaline. This was The Mineralogical Record...volume 51, November–December, 2020 famed Tucson Gem, Mineral and Fossil Showcase in Arizona. The events...and dozens of venues, culminating in the Tucson Gem and Mineral Show held at the Tucson Convention Center |
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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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| 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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| 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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| 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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| of China 14 The Changma Diamond District, Mengyin, Shandong Province, China Peter C. Keller a n d W...Fujian Province, China Alice s. Keller and Peter C. Keller 46 Gem Trade Lab Notes 54 Gem News 57...orticles i n this special issue discuss the many gem materials that are currently found i n the People's...resources of this vast and geologically complex region. Gem resources, in particular, have been a low priority...Chinese in determining and exploiting the country's gem wealth. One consequence of this new interest in gems |
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| region encompasses ·what may be the world's richest gem deposits, and is explored in depth in this pioneering...clearly among the world's richest areas, akin to Sri Lanka and Brazil, which interestingly, share a similar...It is rapidly becoming of major importance to the gem world. East Africa is home to two of the world's...Africa 3 Geological Overview of East Africa's Gem Fields 3 The Tanzanian Shield 6 The Mozambique Belt...Longido, Northern Province, Tanzania 28 Ruby and Sapphire from Umba, Tanga Province, Tanzania 32 Sapphire |
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| Hitge specimen, Bruce Cairncross photo; (bottom) Gem-quality green chromian diopside crystals on large...member of a family that has been in the East African gem and mineral industry for three generations - starting...(Taita), malaya (Samburu), chrome (Taita). of the gem and mineral bounty of East Africa to the world market...established East Africa as an important source of fine gem material. Furthermore, the region has produced some...sources of some interesting material (for example, the gem-quality tourmaline that can be found in Rwanda). |
