CVD Synthetic Diamond with Fancy Vivid Orange Colour
Strong absorptions from N-V centres were the main cause of a CVD synthetic diamond’s pinkish orange bodycolour.
Two Fancy Dark Grey CVD Synthetic Diamonds
Examination of two CVD synthetic diamonds with an unusual Fancy Dark grey colour.
Heavily Irradiated CVD Synthetic Diamond
A look at the first CVD synthetic diamond examined at GIA that has been irradiated to a blue colour.
Large synthetic moissanite with silicon carbide polytypes
Examination of the properties of a synthetic moissanite specimen submitted as a black diamond.
A Large Irradiated Green-Yellow Diamond
GIA's identification of a large diamond as artificially irradiated based on careful spectroscopic analysis and lab database review.
Spring 1991 G&G Lab Notes
This section, from the Spring 1991 issue of Gems & Gemmology, is a compilation of interesting finds from GIA’s laboratories.