Natural-Color Blue, Gray, and Violet Diamonds: Allure of the Deep
Summarizes data collected on more than 15,000 natural blue/gray/violet diamonds examined by GIA during the last decade and examines the mechanisms that produce this color range.
DNA Techniques Applied to the Identification of Pinctada Fucata Pearls from Uwajima, Ehime Prefecture, Japan
Shows how genetic material extracted from small amounts of pearl powder can be a useful indicator of this akoya cultured pearl species.
An Introduction to Photoluminescence Spectroscopy for Diamond and Its Applications in Gemology
Presents the underlying physics and methodology of this analytical technique, which has become an essential tool in identifying treated and synthetic diamonds.
Natural-Color Pink, Purple, Red, and Brown Diamonds: Band of Many Colors
Summarizes data collected by GIA on more than 90,000 natural diamonds in this color range and presents their gemological and spectroscopic properties.
Observations on HPHT-Grown Synthetic Diamonds: A Review
Summarizes statistical data and distinctive features of several thousand gem-quality HPHT synthetic diamonds examined by GIA from 2007 through 2016.
Japanese Jadeite: History, Characteristics, and Comparison with Other Sources
Examines the sources, color, texture, and chemical composition of jadeite from Japanese deposits.
Identification of “Pistachio” Colored Pearls Treated by Ballerina Pearl Co.
A report on the color treatment process for these intensely greenish yellow to yellowish green cultured pearls and the techniques for identifying them.
Bead-Cultured and Non-Bead-Cultured Pearls from Lombok, Indonesia
Documents the retrieval and testing of P. maxima cultured pearls from a Lombok hatchery.
Geographic Origin Determination of Alexandrite
The geographic source of this rare color-change gem has a significant impact on value. Trace element chemistry profiles allow GIA to accurately determine origin for alexandrite from several countries.
Geographic Origin Determination of Emerald
The relative chemical diversity of emeralds from different deposits worldwide allows clear origin determination in most cases. This contribution explains the criteria used by GIA to make geographic origin conclusions for emeralds.