Fall 1985 Gems & Gemology

VOLUME XXI FALL 1985 The quarterly journal of the Gemological Institute of America FALL 1985 Volume 21 Number 3 TABLE OF CONTENTS EDITORIAL 129 The New Australia Richard T. Liddicoat, jr. FEATURE Sapphires from Australia ARTICLES Terrence Coldham Pink Diamonds from Australia Stephen C. Hofer The Biron Hydrothermal Synthetic Emerald Robert E. Kane and Richard T. Liddicoat, jr. REGULAR Gem Trade Lab Notes FEATURES Gemological Abstracts Gem News Book Reviews Suggestions for Authors ABOUT THE COVER: Of thegemstones currently coming from Australia, one of the newest and most exciting is the pink diamond. Stephen Hofer thoroughly examined more than 100 of these stones when they weresubmitted to the GIA Gem Trade Laboratoryin New York earlier this year. He reports on their distinctive color and other gemological characteristics in this special "Australia" issue. The 3.53-ct (VS1)blue diamond on the cover, set in a ring, is surrounded by 36 Australianpink diamonds (2.64 ct total weight). The intensepurple-pink heart-shaped diamondin thenecklaceis also from Australia. It weighs 0.72 ct andis complemented by 03.24-ct briolette and 9.07 ct (total weight) of other diamonds. The jewelry is courtesy of R. Esmerian, Inc., New York. Photograph 0 1985 Harold a) Erica Van Pelt-Photographers, Los Angeles. Typesetting for Gems & Gemology is by Scientific Composition, Los Angeles, CA. Color separations are by Effective Graphics, Compton, CA. Printing is by Waverly Press, Easton, MD. a1985 Gemological Institute of America All rights reserved ISSN 0016-626X FALL 1985 Volume 21 Number 3 EDITORIAL Editor-in-Chief Editor Editor, Gem Trade Lab Notes STAFF Richard T. Liddicoat, Jr. Alice S. Keller C. W. Fryer Associate Editors 1660 Stewart St. Santa Monica, CA 90404 Editor, Gemological Abstracts Peter C. Keller Dona M. Dirlam D. Vincent Manson Telephone: 12 13) 829-2991 John Sinkankas Assistant Editor Editor, Book Reviews Jeffrey M. Uurbank Technical Editor Sally A. Thomas Carol M. Stockton Subscriptions Contributing Editor and Janet M. Fryer, Manager Editor, Gem News Lisa Hebenstreit, Assistant Manager John I. Koivula PRODUCTION Art Director Production Assistant Production Assistant STAFF Susan Kingsbury Linda Manion John McCloy EDITORIAL Robert Crowningshield Anthony R. Kampf Kurt Nassau REVIEW BOARD New York, NY Los Angeles, CA Bernardsville, N1 Pete Dunn Robert E. Kane Glenn Nord Washington, DC Los Angeles, CA Los Angeles, CA Dennis Foltz John Koivula Ray Page Santa Monica, CA Santa Monica, CA Santa Monica, CA Chuck Fryer Henry 0. A. Meyer George Rossman Santa Monica, CA West LaFayette, Indiana Pasadena, CA C. S. Hurlbut, Jr. Sallie Morton James E. Shigley Cambridge, MA San lose, CA Santa Monica, CA SUBSCRIPTIONS Subscriptions in the U.S.A. are priced as follows: $29.50 for one year (4 issues), $82.50 for three years (12 issues), Subscriptions sent elsewhere are $40.00 for one year, $115.00 for three years. Special annual subscription rates are available for all students actively involved in a CIA program: $24.50 U.S.A., $35.00 elsewhere. Your student number must be listed at the time your subscription is entered. Single issues may be purchased for $8.00in the U.S.A., $1 1.OO elsewhere. Discounts aregiven for bulk ordersof 1001 more of any one issue. A limited number of back issucs of C&G are also available for purchase. Please address all inquiries regarding subscriptions and the purchase of single copies or back issucs to the Subscriptions Manager. MANUSCRIPT Gems e) Gemology welcomes the submission of articles on all aspects of the field. Please see the Suggestions for Au- SUBMISSIONS thors in the Spring 1985 issue of the journal, or contact the editor for a copy. Letters on articles published in Gems a) Gemology and other relevant matters are also welcome. COPYRIGHT Abstracting is permitted with credit to the source. Libraries are permitted to photocopy beyond the limits of U.S. copyright law for private use of patrons. Instructors are permitted to photocopy isolated articles for noncommercial AND REPRINT classroom use without fee. For other copying, reprint, or republication permission, please contact the Editor. PERMISSIONS Gems a) Gemology is published quarterly by the Gemological Institute of America, a nonprofit educational organization for the jewelry industry, 1660 Stewart St., Santa Monica, CA 90404. Application to mail at second class postage rates is pending in Santa Monica, CA 90404 and at additional mailing offices. Postmaster: Return undeliverable copies of Gems Ãˆ Gemology to 1660 Stewart St., Santa Monica, CA 90404. Any opinions expressed in signed articles are understood to be the views of the authors and not of the publishers. The New Australia or generations, Australia has been the prime producer of fine opal, includ- Fing the only notable black opal. Recently, it has become a major supplier of gem-quality diamonds. And Australian chrysoprase is unmatched in quality by that from any other source. Australia is also rich in technological resources: Scientists on the staff of the government's Commonwealth Scien- tific and Industrial Research Organization (CSIRO)were the first to synthe- size opal with play of color. Today, the international gemological community is beginning to experience the full impact of Australian activities. In recognition of the major role that Australia now plays in all aspects of gemology, this issue is devoted to some of the most recent contributions of Australia to gemology. We are pleased to present comprehensive articles on the many fine sapphires of Australia, on ' the beautiful new pink diamonds from Argyle, and on the new Biron hydrothermal synthetic emerald manufactured in Western Australia. Now that the desert interior and Western Australia are beginning to be opened up, much more in the way of new gem discoveries may be expected. Already, we have heard of two new emerald finds in Western Australia, and a signifi- cant deposit of amethyst. The fine translucent ruby recovered near Ayers Rock in central Australia a few years ago has also attracted considerable attention. In my opinion, Australia is an exciting new frontier that has the potential over the next few generations to become as prolific a supplier of gem materials as Brazil or East Africa. Richard T. Liddicoat, Jr. Editorial GEMS & GEMOLOGY Fall 1985 129 SAPPHIRES FROM AUSTRALIA By Terrence Coldham During the last 20 years, Australia has ew people realize that Australia is one of the major assumed a major role in the production of F producers of sapphire on the world market today. Yet a blue sapphire. Most of the gem material fine blue Australian sapphire (figure 1)competes favorably comes from alluvial deposits in the Anal<ie with blue sapphire from noted localities such as Sri Lanka, (central Queensland) and New England (northern New South Wales) fields. Mining and virtually all other hues associated with sapphire can be techniques range from hand sieving to found in the Australian fields (figure 2). In fact, in the highly mechanized operations. The rough is author's experience it is probable that 50% by weight of usually sorted at the mine offices and sold the sapphire sold through Thailand, usually represented directly to Thai buyers in the fields. The as originating in Southeast Asia, were actually mined in iron-rich Australian sapphires are predom- Australia. inantly blue (90%),with some yellow, some In spite of the role that Australian sapphire plays in the green, and a very few parti-colored stones. world gem market, surprisingly little has been written The rough stones are commonly heat about this indigenous gem. This article seeks both to de- treated in Thailand to remove the silk. scribe the Australian material and its geologic origins and Whileproduction has been down duringthe to introduce the reader to the techniques used to mine the last two years because of depressed prices combined with higher costs, prospects for material, to heat treat it prior to distribution, and to the future are good. market it worldwide. HISTORY The two main sources for sapphire in Australia are the New England fields, in northern New South Wales, and the Anakie fields, in central Queensland. Large-scale com- ABOUT THE AUTHOR mercial mining has been successful at these two fields Mr. Coldham is the owner of Sapphex P.L., a only. Geographically, the two areas are quite different. The Sydney-based gemstone merchant and lapidary specializing in Australian rough and cut sapphire. Anakie fields are in a semi-arid area of gently undulating Acknowledgments: The author gratefully low hills, while the New England fields cover an area of acknowledges the considerable help provided by tablelands consisting of rich grazing land and fertile river Tom Nunan (Inverell)and the Jarugosol family flats that comprise some of the best agricultural country in (Bangkok)for technical information;Gordon Streight, Dr. Brenda Franklin, and members of the Australia. Mineralogy Section of the Australian Museum for While sapphire was first reported from Inverell (NSW] proofreading and advice; Bill Scheos, Rod in 1854, the first sapphire mining started at the Anakie Brightman, Noni Primrose, and the Department of Mineral Resources (NSW) for assistance in fields almost 40 years later. In 1873, Archibald John presentation; and Sandra Pike for typing without Richardson found sapphire near the town of Anakie (Mon- complaint. teagle, 19791, about 50 km to the west of the township of Unless otherwise noted, photos are by the author. Emerald in central Queensland. Local lore has it that Em- 07985 Gemological Institute of America erald was so named because green sapphires found in the 130 Sapphires from Australia GEMS & GEMOLOGY Fall 1985 Figure 1. Twofine blue sapphires, 1.11 ct and 1.61 ct, respectively, from the New England fields, New South Wales, Australia. Photo 0 Tino Hammid. area were originally thought to be emeralds.

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