 | | Journal (article/letter/editorial) | | and mineral inclusions in corundum from gem gravels in Sri Lanka A. A. DE MAESSCHALCK AND I. S. OEN Institute...inclusions were studied in seven gem corundums from gravels of three areas in Sri Lanka. All fluid inclusions are...fluid inclusions, gem gravels, Sri Lanka. Introduction SRI LANKA is famous for its gem corundum, which...other gemstones in alluvial, eluvial and residual gravels on granulite facies rocks of the Highland Series...Kumarapeli, 1960); in a pegmatite near Kolonn6, Ratnapura (Gunaratne, 1976); as an accessory mineral in |  | 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...Pardieu/GIA; (E) E. Gaillou/ENSMP. Badakshan Province in Afghanistan (Spencer 1937). In Roman times...SPINELS IN MARBLE FIG. 2. Location of pink and red gem spinel deposits (large star) and occurrences (small |  | | Book | | 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; | | | Book | | 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; |  | | Report (issue) | | andalusite, biotite, phlogopite, magnetite, ilmenite, hematite, rutile. Distribution: Some localities for well-studied...Bok se Puts Farm, Namaqualand, Cape Province, South Africa. Gem crystals from Itrongahy, near Betroka...Madagascar. From gem gravels of the Matale, Ratnapura, and Embilipitiya districts, Sri Lanka. In the Harts |  | | Journal (issue) | | 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' |  | | Journal (issue) | | 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 |  | | Journal (issue) | | 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 |  | | Journal (issue) | | 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 |  | | Book | | 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 |  | | Book | | 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 |  | | Book | | 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, |  | | Journal (issue) | | 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 |  | | Journal (issue) | | Tribute to Robert M. Shipley, Jr. The Chanthaburi-Trat Gem Field, Thailand Peter C. Keller 197 Gemstones with...Alexandrite Effect E. Giibelin and K. Schmetzer 204 Gem-Quality Grossular Garnets D. Vincent Manson and Carol...Crystal: The Van Pelt Collection John Sinkankcis 221 Gem-Quality Friedelite from the Kalahari Manganese Field...REGULAR FEATURES Gem Trade Lab Notes Editorial Forum Gemological Abstracts Book Reviews Gem News Index to...Liddicoat, Jr. Associate Editor Peter C. Keller Editor, Gem Trade Lab Notes Chuck Fryer Editor, Gemological Abstracts |  | | Book | | 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 |  | | Journal (issue) | | 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 |  | | Journal (issue) | | NOTES FROM THE LABORATORY By A. E. FARN, F.G.A. The Gem Testing Laboratory, London Chamber of Commerce and...Apricot Province ___________ Teita Province Morgans Mine Mine Kenya Kenya Teita Province Bridges Mine...stone's absorption of light. But the colour of a gem is due to the light it transmits a n d only in a...California, has been allowed to examine the electronic gem-tes ter called the Jeweler's Eye. This instrument...to point out that refractive indices, as given in gem textbooks, are based on the index as measured using |  | 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...and chlorite (Naxos) and chloritoid, ilmenite, hematite, ulvospinel, rutile and zircon (Ikaria). The main...–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 |  | | Book (edition) | | 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 |  | | Journal (issue) | | 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 |  | | Book | | 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 |  | | Journal (issue) | | 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 |  | | Book | | Marvel over India's maharajahs, the world's greatest gem collectors, for whom no price was too great. Explore...star ruby on public display. A product of Sri Lanka's gem gravels, today it resides at the Smithsonian in...301 has yet to be surpassed for ruby. Today the gem is said to be 1n the personal collection of one of...of pure celestial blue Set i11 a golden band; A gem that owes its beauty to No lapidary's art, But to...origin is uncertain, but probably emanates from Sri Lanka. Today it rests in New York's Amer1can Museum |  | | Journal (issue) | | 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 |  | | Book | | 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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