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.
Cutting Diffraction Gratings to Improve Dispersion (“Fire”) in Diamonds
A new microlithography process developed to create high-resolution diffraction grating patterns on portions of certain facets can improve the dispersion of light and thus the amount of “fire” in a diamond.
CVD Synthetic Diamonds from Gemesis Corp
An examination of the gemmological and spectroscopic properties of CVD synthetic diamonds from Gemesis Corp.
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.
Abstracts; Summer 2009
This article, from the Summer 2009 issue of Gems & Gemmology, is a compilation of abstracts of important gemmology-related articles published outside of Gems & Gemmology.
GE POL Diamonds: Before and After
This article explores and identifies the changes that type IIa GE POL diamonds experience before and after HPHT annealing.
De Beers Natural versus Synthetic Diamond Verification Instruments
Two instruments have been developed at De Beers DTC Research Centre, Maidenhead, to distinguish synthetic diamonds from natural diamonds.
De Beers near Colourless-to-Blue Experimental Gem-Quality Synthetic Diamonds
De Beers has produced a faceted synthetic gem-quality diamond that could go unrecognised without careful gemmological testing.
Marine mining of diamonds off the west coast of Southern Africa
It is anticipated that production of diamonds from the sea will increase substantially in the future.