Senior Research Scientist, GIA
After obtaining a PhD in Geology from Stanford University, Dr. Palke began his gemological career as a Postdoctoral Research Associate at the Gemological Institute of America where he is now the Senior Manager of Colored Stone Research. In this role, Dr. Palke leads GIA's research efforts into geographic origin determination for rubies, sapphires, emeralds and other colored stones as well as improving criteria for identification of treatments for colored stones. Dr. Palke is a regular contributor to Gems & Gemology and serves on the journal's editorial review board.
Color treatment by artificial irradiation has been an issue in the sapphire trade for over a half century. Early on methods were developed to remove potentially unstable color in treated sapphires. However, recent developments including irradiation of pink sapphire to produce a temporary padparadscha-like color and irradiation of some rubies has resurfaced this issue and created uncertainties in the market. In this presentation Dr. Aaron Palke will provide an overview of the ins and outs of artificial irradiation and color instability in sapphire, as well as providing practical tools for identifying such stones.
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