On July 6, 2009, the DC Chapter of the GIA Alumni Association was privileged to hear from Dr. Lore Kiefert, Director of the AGTA Gemological Testing Center.
Her presentation, entitled “New and Old Gemstone Sources – New and Renewed Finds”, profiled the past, present, and future with respect to gemstone origins.
The resultant tour spanned the globe, considering historic locales such as Kashmir, Burma, and Russia, as well as more contemporary finds in East Africa, the Himalayas, Canada, and the U.S. Dr. Kiefert also highlighted the issues, opportunities, and controversies that can emerge with each new discovery, including matters such as quality, quantity, identification, and nomenclature.
Dr. Kiefert structured her presentation according to gemstone variety, commencing with sapphire and continuing through, inter alia, ruby, emerald, demantoid, amethyst, and tourmaline. In general, Dr. Kiefert would introduce each gem with a summary of classic sources, indicating the location and geology of the deposits and showing in detail the inclusion profile characteristic for stones from the location. She would then explain newer finds for the material, demonstrating once again typical, and potentially, distinguishing inclusions.
Lastly, to the extent relevant, Dr. Kiefert would explain the contribution to be made by advanced testing techniques in separating stones from the various sources, including use of UV-VIS and FTIR spectroscopy as an aid in chemical analysis.
With respect to sapphire, for instance, classic sources include Kashmir, Ceylon, and Burma. However, Kashmir has also more recently been the source for newer production as well, although largely of lower quality. Concerning ruby, developments of late have spanned the legal as well as the geographical spectrum. As importation from the classic source of Burma has been banned in the United States, alternative finds in places such as Tajikistan, Tanzania (Winza), and even Greenland have received increasing focus.
With emerald, classic sources such as Columbia have been supplemented with a recent discovery in Canada. Regarding demantoid, supply from the classic Russian mines has been augmented by material from Iran. Amethyst, while prolific in many regions, is now being seen from Cambodia in a relatively atypical pinkish color.
Dr. Kiefert closed her presentation with a discussion of copper-bearing or “paraiba” tourmaline, sourced now not only from Paraiba, Brazil, but also from Nigeria and Mozambique, affording insight into both characteristics of the material itself and the resultant nomenclature controversy. The DCGIA Chapter was truly the beneficiary of a wealth of gemological information from one of the foremost experts in the field. Thank you, Dr. Kiefert.
Welcom Back Tony & Donna
Summary prepared by Andrea Blake
Photos by Melanie Marts