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.
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.
Saltwater Pearls from the Pre- to Early Columbian Era: A Gemmological and Radiocarbon Dating Study
Examines 85 saltwater natural pearls, reportedly harvested from the Caribbean islands off the coast of Venezuela during the early 16th century, to determine their age.
CVD Synthetic Diamonds from Gemesis Corp
An examination of the gemmological and spectroscopic properties of CVD synthetic diamonds from Gemesis Corp.
GIA’s Symmetry Grading Boundaries for Round Brilliant Cut Diamonds
A presentation of parameters used to support GIA's symmetry grading system.
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.
The French Blue and the Hope: New Data from the Discovery of a Historical Lead Cast
With the use of modern tools and technology, this article sheds light on the history and provenance of both the French Blue and the Hope diamonds.
The Wittelsbach Blue
This article describes what is known about the Wittelsbach Blue since it was first reported in 1666, and the gemmological information released to date on this diamond.
Colour Grading “D-to-Z” Diamonds at the GIA Laboratory
This article discusses the history and ongoing development of GIA's colour grading system, and explains how its laboratory applies it.
Latest-Generation CVD-Grown Synthetic Diamonds from Apollo Diamond Inc.
High-quality CVD-grown diamonds, comparable in colour and clarity to natural diamonds, can be identified using a combination of gemmological and spectroscopic properties.