Dr. James Shigley

Dr. James Shigley is a distinguished research fellow at the Gemological Institute of America in Carlsbad, California. GIA is a non-profit educational and research institute founded in 1931 that supports the jewelry industry and the general public with information on gem materials. Prior to joining GIA in 1982, Dr. Shigley studied geology as an undergraduate at the University of California, Berkeley, and later received his doctorate in geology from Stanford University.


He is the author of articles on diamonds and other gemstones, and is a well-known speaker on gemological topics to both professional and general audiences. Dr. Shigley helps direct GIA’s research activities on the identification of natural, synthetic, and treated diamonds, as well as colored gemstones.

Identifying Synthetic Diamonds: Past Progress and Current Challenges


The identifying features of natural and synthetic diamonds are related to the period of time during crystal formation when the diamond was subjected to high temperatures (>1000°C). In nature, diamonds are kept at these temperatures in the earth for millions of years. In contrast, synthetic diamonds only experience these high temperatures for a limited time during growth (generally up to a few weeks). This presentation will illustrate those diagnostic features that reveal the long-term versus short-term growth history of natural and synthetic diamonds.

Impressions from the first EGS 2007 in Idar-Oberstein

Register for the European Gemmological Symposium
on May 24 – 26, 2019 in Idar-Oberstein.

During the two days’ conference, you will enjoy numerous internationally recognized and distinguished speakers, as well as a broad spectrum of subjects including diamonds, coloured stone, pearls and jewellery.

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