Selected Reviews

" The book describes the processes involved in the heat treatment of rubies and sapphires. This is very nearly a step-by-step recipe for the treatment as all stages are illustrated on each side of the text which occupies the centre of each page. The all-colour illustrations and the strong red page headers make the book seem quite aggressive and the effect is memorable.
The text is, too, or should be as this is probably the best account so far of this type of treatment. Several authorities are cited and the dangers of doing it yourself are emphasized in a general disclaimer. There is a glossary and a short bibliography. The final part of the text deals with identifying treatment of this kind: disclosure and market value are also briefly discussed. Questions and answers cover several of the areas which gemologists could well study. M.O' D" -Journal of Gemmology, Vol. 2 , April 2004

"In this well illustrated, 48-page soft cover, one of world's pioneering heat treaters of ruby and sapphire, Ted Themelis, ‘lifts the lid' on some of the basics of this colour and clarity enhancement process. The information offered by Mr. Themelis is most welcome--particularly as it emphasises the complex role that fluxes of various type play in the heat treatment (flux enhancement) regime for ruby and sapphire.
Following a couple of introductory pages that cover the historical background of heat treating corundum, and questions and answers with respect to flux treatment of ruby and sapphire, the author's first major topic of discussion is the role flux plays in enhancing the appearance of a heat treated corundum. Six pages of text are then devoted to brief descriptions of the various fluxes that are and have been used in this heat treatment process. A useful description of how ruby and sapphire are prepared for heat treatment then precedes an informative description of the heat treatment process. Next, how acid is used to remove tell-tale flux glass residue from filled or partly filled surface-reaching fractures is described and illustrated in some detail. This is important information, for this commercially important step in the heat treatment process is rarely described in the gemological literature. The little-appreciated topic of silica contamination of heat treated corundum follows, and possible causes for this potentially troublesome contamination are suggested. By far the major part of the text of this book (pages 22 – 37) have been devoted to well illustrated descriptions of the features of flux-enhanced rubies and sapphires from Mong Hsu and Mogok (Myanmar), Vietnam, Sri Lanka, and several East Africa countries. Some illustrated comments on the features of synthetic flux grown corundum complete this part of the book. Gemmologists and gemology students will find the author's detailed illustrated description of the fissure filling process in corundum (p. 26) most educational. Useful descriptions of flux glass infillings of surface cavities, and surface alterations due to the flux based heat treatment are then provided. The text of this very informative small book is completed by short descriptions of how to grade flux filled surface-reaching fractures, the stability of flux-enhanced rubies and sapphires, the comparative market value of heat treated v unheat treated rubies and sapphires, problems and recommendations associated with disclosure of this treatment and finally a Summary & Conclusion that specifies the identifying features of this treatment.

As a book 'designed to educate the reader on flux process applied to rubies and sapphires from the practical standpoint', this book certainly succeeds; for its content is as unique and it is useful. Thank you Ted for ‘lifting the lid' on this long used and occasionally contentions value enhancement process for ruby and sapphire. Ed." -Australian Gemmologist, Vol. 22, Number 2, April-June 2003