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Editor
Dr. A. Peretti, FGG, FGA, Eur Geol
GRS Gemresearch Swisslab AG, P.O.Box 4028, 6002 Lucerne, Switzerland
Adolf@Peretti.ch
Previous Journal and Movie
This journal follows the rules of the Commission on New Minerals and Mineral Names of the IMA in all matters concerning mineral names and nomenclature.
Distributor
GRS (Thailand) Co., LTD
257/919 Silom Rd., JTC Building
Bangkok 10500, Thailand.
Journal and Website Copyrighted by GRS (Thailand)
Co. LTD, Bangkok, Thailand and GRS Gemresearch
Swisslab AG, Lucerne, Switzerland
This report is available online at
www.gemresearch.ch
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ISBN 978-3-9523359-9-4
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Message from the Editors Desk: When trace element research matters most
When copper bearing tourmalines were found 20 years ago in the state of Paraíba in Brazil, they intrigued by their “neon”-blue color and soon became known as “Paraíba” tourmalines in the trade. In the years before and into the new Millennium, these tourmalines have emerged to become one of the most valuable and demanded gems, comparable to prestigious rubies and sapphires. In the last couple of years an unprecedented tourmaline boom has occurred due to the discovery of new copper-bearing tourmaline deposits. The name “Paraíba” tourmaline was originally associated only with those copper-bearing tourmalines (or “cuprian-elbaites”), which were found in the state of Paraíba (Brazil). New mines were subsequently encountered in Rio Grande do Norte in Brazil, as well as in Nigeria and in Mozambique. The market and the laboratories were split on the issue whether to call the newly discovered neon-blue colored tourmalines “cuprian-elbaites” or “Paraíba tourmaline” regardless of origin. While this controversy initiated the first high-profile law suite in the USA (currently dropped), the debate on Paraíba tourmalines progressed into a new direction. A first theory emerged on the Internet and in a seminar at the Tucson show in 2009, arguing that Paraíba tourmaline may have been diffusion-treated.
In 2006, GRS has announced on its website, that it had achieved to apply a chemical testing procedure which enables to distinguish “Cuprian-Elbaites” from different origins, based on an extensive research program. In the light of the new controversy, GRS and the laboratory of Inorganic Chemistry and Applied Biochemistry from the ETH Zurich decided to publish this specialized research report in full length.
Although some chemical data on the origin of Paraíba tourmalines have been published elsewhere, we have chosen a different approach in our research and combined the capabilities of different analytical techniques. We concentrated on the analysis of element variations within single crystals of copper-bearing tourmalines, which contain pronounced color zoning and extensive chemical variability. Fortunately, it was possible to solve two different issues at the same time: Establish criteria for origin determination of “Paraíba tourmalines” as well as to characterize natural chemical zoning patterns within these tourmalines. We are confident that our research will prevent further confusion between “chemical fingerprints” induced by nature and those claimed to be potentially inflicted by treatment techniques.
Adolf Peretti
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Foreword