Crisp, concise and authoritative, this comprehensive up-to-date work reveals a wealth of facts on the "new" beryllium treatment method practiced in Thailand on rubies and sapphires. This work provides key coverage and detail needed for the gemologist, jeweler, gem trader and just about anyone involved in the gem and jewelry business. For the gemologist, this work broadens the existing understanding of this complex, diverse and controversial issue. It illustrates numerous inclusion color photomicrographs contributing invaluable reference data that every library should have.
For the gem trader, this work provides the information needed to enhance their knowledge in everyday dealing with gems to avoid costly mistakes. For the jeweler this edition illustrates the complexity of the issue and provides accurate information and full disclosure to jewelry merchandisers, salespersons and consumer.
"A unique, well balanced and readable text covering both the thermochemical theory and the practical details necessary for the heat treatment of corundum and its detection. Highly recommended."
-Peter G. Read, C. Eng, MIEE, MIERE, FGA
"This book has a truly astonishing amount of unpublished experimental data on a subject of broad interest, in theory as well as in practice. This work is of particular interest for gemologists, geologists, and the mineralogists. It also, may be of invaluable use for those involved in the gem trade."
-V. de Michele, Istituto Gemmologico Italiano
"This is the first book to deal with both the practical heat treatment of corundum and its technical/scientific aspects. The great number of empirical results presented makes it possible for the reader to fully appreciate the complexity of the subject. The author has carried out experiments on all available samples in order to record variations in the color mechanism response As Ted Themelis shows, heat treatment cannot work wonders; however, under controllable conditions the results in many cases may cause surprise.
The reader of this volume, who is looking for a sure-fire recipe for treating his particular specimens will be started by the detailed descriptions of the many different materials and their specific methods of treatment. Some gemologists and dealers in precious stones will also be surprised by both the extensive list of corundum deposits, some of them relatively unknown, and by the characterization of the respective gems.
This book by Ted Themelis is an important addition to the list of technical publication on gemstones. As a text, it is recommended to every gemologist who has an open mind to the current developments in the field of corundum heat treatment." -Dr. H A. Hanni, SSEF - Swiss Gemmological Institute.