Themelis’s Book Reviewed

One of the more important gem topics found in print lately has been the diffusion treatment of sapphire. To that end, author and laboratory gemologist Ted Themelis, owner of Gemlab Inc. in Bangkok, Thailand, has produced his second book on the topic, which received—in the same review—both a recommendation for purchase and a condemnation for its lack of accurate scientific analysis.

There are many new gem books in the market, but none more important than this one, even though it’s gotten a bad rap. In the latest issue of Gems & Gemology, Dr. John Emmett, one of the leading sapphire experts in the world and a friendly acquaintance of Themelis, had a chance to review Flux-Enhanced Rubies and Sapphires. In his review, Emmett compliments Themelis’s images of before-and-after laboratory experiments, which give the reader insight into what actually happens with color and clarity changes when corundum is cooked using different fluxes. However, Emmett also said Themelis’s chemistry discussion failed “abysmally.” He explained that “if you have a background in inorganic chemistry, it will amuse; if you don’t, it will confuse.” Nevertheless, Emmett says this book should be on every gemologist’s bookshelf, if only for the pictures, and we agree.

For more information on how to obtain Themelis’s books, log onto his Web site at