Black Diamonds from Marange (Zimbabwe): A Result of Natural Irradiation and Graphite Inclusions
Characterises a suite of 40 natural brown to black diamonds from this deposit so that they can be distinguished from suspected treated black diamonds.
Natural-Colour Blue, Grey and Violet Diamonds: Allure of the Deep
Summarises data collected on more than 15,000 natural blue/grey/violet diamonds examined by GIA during the last decade and examines the mechanisms that produce this colour range.
The Very Deep Origin of the World’s Biggest Diamonds
Explores an exceptional family of diamonds, referred to as “CLIPPIR” (Cullinan-like, Large, Inclusion-Poor, Pure, Irregular and Resorbed), that formed in a super-deep environment.
The “Type” Classification System of Diamonds and Its Importance in Gemmology
Knowledge of type allows gemmologists to better evaluate if a diamond might be treated or synthetic, and whether it should be sent to a laboratory for testing.
Discovery and Mining of the Argyle Diamond Deposit, Australia
Australia’s Argyle mine has set records for volume since its establishment in 1983, and is additionally noted for its rare pink diamonds.
Colour Alterations in CVD Synthetic Diamond with Heat and UV Exposure: Implications for Colour Grading and Identification
In response to heat and UV exposure, some synthetic diamond gemstones grown by chemical vapor deposition exhibit large, reversible changes in colour.
Identification of HPHT-Treated Yellow to Green Diamonds
Greenish yellow to yellowish green HPHT-treated diamonds exhibited highly saturated body colour, well-defined brown to yellow octahedral graining and visual evidence of heating, among other characteristics.
The Gemmological Properties of the De Beers Gem-Quality Synthetic Diamonds
Examination of a group of 14 brownish yellow, yellow and greenish yellow synthetic diamonds reveals distinctive gemmological properties.
“Fluorescence Cage”: Visual Identification of HPHT-Treated Type I Diamonds
HPHT-treated type I diamonds of various colours may exhibit unusually intense fluorescence at the facet edges and junctions.
A Gemmological Study of a Collection of Chameleon Diamonds
Chameleon diamonds are among the rarest of gem diamonds.