G EMS & G VOLUME XLIII SUMMER 2007 EMOLOGY S UMMER 2007 P AGES 95–196 Global Rough Diamond Production V Durability Testing of Filled Emeralds OLUME Chinese Freshwater Pearl Culture 43 N O. 2 THE QUARTERLY JOURNAL OF THE GEMOLOGICAL INSTITUTE OF AMERICA ® Summer 2007 VOLUME 43, NO. 2 95 LETTERS _____________ FEATURE ARTICLES _____________ 98 Global Rough Diamond Production since 1870 Carat Points A. J. A. (Bram) Janse Reports and analyzes annual production statistics (by carat weight and value) for the world’s most significant diamond sources, through 2005. 120 Durability Testing of Filled Emeralds Mary L. Johnson A long-term, systematic study of the stability and durability of nine common pg. 99 emerald-filling substances. NOTES AND NEW TECHNIQUES ________ 138 Continuity and Change in Chinese Freshwater Pearl Culture Doug Fiske and Jeremy Shepherd Reviews recent developments in China’s freshwater cultured pearl production, including the new “fireball” cultured pearls. RAPID COMMUNICATIONS ________ 146 Yellowish Green Diopside and Tremolite from Merelani, Tanzania Eric A. Fritz, Brendan M. Laurs, Robert T. Downs, and Gelu Costin pg. 140 149 Polymer-Impregnated Turquoise Kyaw Soe Moe, Thomas M. Moses, and Paul Johnson REGULAR FEATURES _____________________ 153 Lab Notes Diamond with bimineralic inclusions • HPHT-treated type Ia diamond with a green compo- nent caused by the H2 defect • Diamond with intense “rainbow graining” • Natural color hydrogen-rich blue-gray diamond • Type IIa diamond with intense green color introduced by Ni-related defects • Diamond with zigzag cleavage • HPHT-grown synthetic diamond crystal with unusual morphology and negative trigons • Idocrase in jadeite • Opal with unusual structure 162 Gem News International Bar code technology applied to diamonds • U.S. Supreme Court ruling may affect viability of some diamond cut patents • First discovery of amazonite in Mexico • Astorite—A rhodonite-rich rock from Colorado • Color-change bastnäsite-(Ce) from Pakistan • Citrine pg. 154 with pyrite inclusions • Unusual danburite pair • Fluorite from Ethiopia • Heliodor and other beryls from Connecticut • Cat’s-eye K-feldspar and other chatoyant gems from Tanzania • Green opal • Chinese akoya cultured pearls • Pyrope-almandine from Tanzania • Pink-to-red tourmaline from Myanmar • Glass object with circular bands • Heat-treated Kashan flux-grown synthetic ruby • Synthetic star sapphire with hexagonal features • Pink synthetic spinel colored by iron • A new imitation of Imperial topaz • KPMG report on the global jewelry industry 184 Thank You, Donors 185 Book Reviews 188 Gemological Abstracts pg. 170 ® EDITORIAL Editor-in-Chief Editor Editors, Lab Notes STAFF Alice S. Keller Brendan M. Laurs Thomas M. Moses [email protected] The Robert Mouawad Campus Shane F. McClure Managing Editor 5345 Armada Drive Editor, Gem News International Thomas W. Overton Carlsbad, CA 92008 Brendan M. Laurs [email protected] (760) 603-4503 [email protected] Technical Editor Editors, Book Reviews Associate Editor Sally Magaña Susan B. Johnson Stuart Overlin [email protected] Jana E. Miyahira-Smith [email protected] Thomas W. Overton Consulting Editor Circulation Coordinator Carol M. Stockton Debbie Ortiz Editors, Gemological Abstracts Contributing Editor (760) 603-4000, ext. 7142 Brendan M. Laurs James E. Shigley [email protected] Thomas W. Overton PRODUCTION Art Director Production Assistant Website: STAFF Karen Myers Allison DeLong www.gia.edu EDITORIAL Shigeru Akamatsu Jaroslav Hyr`´sl Thomas M. Moses REVIEW BOARD Tokyo, Japan Prague, Czech Republic New York, New York Edward W. Boehm A. J. A. (Bram) Janse Mark Newton Solana Beach, California Perth, Australia Coventry, United Kingdom James E. Butler Alan Jobbins George Rossman Washington, DC Caterham, United Kingdom Pasadena, California Alan T. Collins Mary L. Johnson Kenneth Scarratt London, United Kingdom San Diego, California Bangkok, Thailand John Emmett Anthony R. Kampf James E. Shigley Brush Prairie, Washington Los Angeles, California Carlsbad, California Emmanuel Fritsch Robert E. Kane Christopher P. Smith Nantes, France Helena, Montana New York, New York Henry A. Hänni Lore Kiefert Christopher M. Welbourn Basel, Switzerland New York, New York Reading, United Kingdom Subscriptions to addresses in the U.S. are priced as follows: $74.95 for one year (4 issues), $194.95 for three years (12 issues). SUBSCRIPTIONS Subscriptions sent elsewhere are $85.00 for one year, $225.00 for three years. Canadian subscribers should add GST. Special rates are available for GIA alumni and current GIA students. 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DATABASE Gems & Gemology’s impact factor is 1.762 (ranking 5th out of the 25 journals in the Mineralogy category), according to Thomson Scientific’s 2005 Journal Citation Reports (issued June 2006). Gems & Gemology is abstracted by the following: COVERAGE Cambridge Scientific Abstracts, CSA Illumina, Chemical Abstracts Service, GEOBASE, Elsevier Scopus, GeoRef, Ingenta, Mineralogical Abstracts, and Thomson Scientific products (Current Contents: Physical, Chemical & Earth Sciences and Science Citation Index–Expanded, including the Web of Science). For a complete list, see www.gia.edu/gemsandgemology. MANUSCRIPT Gems & Gemology welcomes the submission of articles on all aspects of the field. Please see the Guidelines for Authors on our SUBMISSIONS Website, or contact the Managing Editor. Letters on articles published in Gems & Gemology are also welcome. Abstracting is permitted with credit to the source. 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Any opinions expressed in signed articles are understood to be the opinions of the authors and not of the publisher. ABOUT For centuries, emeralds have been oiled to mask their abundant inclusions and improve their apparent clarity. A wide range of emerald-filling substances are used today, with varying effectiveness. In this issue, Dr. Mary Johnson compares the stabili- THE OVER C ty and durability of nine common emerald-filling substances. Shown here is a pair of emerald and diamond earrings; the emeralds range from 4 to 18 ct. Courtesy of H. Stern, New York and Rio de Janeiro. Photo © Harold & Erica Van Pelt. Color separations for Gems & Gemology are by Pacific Plus, Carlsbad, California. Printing is by Allen Press, Lawrence, Kansas. © 2007 Gemological Institute of America All rights reserved. ISSN 0016-626X Letters ANNOUNCING GEMS & GEMOLOGY “RAPID COMMUNICATIONS” The current issue marks the beginning of a new feature for G&G. “Rapid Communications” are short articles (2–3 pages) that provide brief descriptions of notable gem materials, localities, and identification or treatment tech- niques—as well as related topics such as museum exhibits and historical jewelry—as quickly as possible and in a readily accessible format. If a manuscript is submitted for Rapid Communications no later than eight weeks before the print date of an issue, and is deemed publishable by the editors and the reviewers, every effort will be made to include it in that issue. We feel that readers and authors alike will benefit from the expedited publication of brief, high-quality research results in Gems & Gemology. For more information, visit www.gia.edu/gemsandgemology and click on “Publishing in G&G.” Brendan M. Laurs, Editor CULTURED PEARL TERMINOLOGY For clarity’s sake, I proposed several changes that appear When dealing with gemologists, students, and people in the in the new CIBJO Pearl Book: pearl trade, I find that most—despite their education about • Omission of the terms nucleus, nucleation, bead nucleat- pearls—have incorrect and misleading ideas about how a cul- ed, tissue nucleated tured pearl is formed and the meaning of certain terms. • Use of the term grafting for the introduction of mantle- In Gems & Gemology, the terms bead nucleated and tis- tissue cells (with