Separation of Black Diamond from NPD Synthetic Diamond
DiamondView is used to differentiate a Fancy black natural diamond from its NPD synthetic counterparts.
Spring 2015 G&G Examines Blue Spinel, Chinese Jewellery Design and the Latest in Synthetics
G&G Brief presents an overview of the content of the Spring 2015 issue of Gems & Gemology.
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.
Xenotime Inclusion in Yellow Diamond
Presents what is believed to be the first report of a xenotime inclusion in gem-quality diamond.
Mixed-Type Cape Diamond
A Fancy orangey-yellow “cape” diamond featured an unexpected 480 nm band, a defect normally associated with orange colour.
Large synthetic moissanite with silicon carbide polytypes
Examination of the properties of a synthetic moissanite specimen submitted as a black diamond.
Black diamond with unusual colour origin
This black diamond's colour was produced by natural radiation stains, an unusual cause of colour.
Strong Colour Zoning in Diamond Reflects Complex Growth Environment
A report on a 2.08 ct emerald-cut diamond graded as fancy dark orangey brown.
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.