Feature
Gems & Gemology, Fall 1993, Vol. 29, No. 3
Two Treated-Color Synthetic Red Diamonds Seen in the Trade
Thomas M. Moses, Ilene Reinitz, and Emmanuel Fritsch, James E. Shigley
Two dark brownish red faceted stones, recently submitted to the GIA Gem Trade Laboratory for standard origin-of-color reports, were found to be treated synthetic diamonds. This conclusion was based on observations of: patterns of zoned color, U. V. luminescence, and graining; metallic inclusions; and certain bands in the visible- and infrared-range absorption spectra. We believe that this is one of the first published reports of treated-color synthetic diamonds seen as faceted gems. For some of the gemological features described here, such as visible-range spectra with sharp absorption bands, this is one of the first reported occurrences in gem-quality synthetic diamonds.
