Fluorescence Produced by Optical Defects in Diamond: Measurement, Characterization, and Challenges
How variations in UV lamp output can affect observed fluorescence color and intensity.
Gray-To-Blue-To-Violet Hydrogen-Rich Diamonds from the Argyle Mine, Australia
The Argyle diamond mine is the only known source of type IaB hydrogen- and nitrogen-rich diamonds colored gray to blue to violet.
Digital Photomicrography for Gemologists
A guide to capturing gem inclusion scenes using practical equipment and techniques and the appropriate image-refining software.
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.
Color Grading of Colored Diamonds in the GIA Gem Trade Laboratory
How GIA’s Gem Trade Laboratory grades colored diamonds, including an expanded color grading terminology, is explained.
De Beers near Colorless-to-Blue Experimental Gem-Quality Synthetic Diamonds
De Beers has produced a faceted synthetic gem-quality diamond that could go unrecognized without careful gemological testing.
Treated-Color Pink-To-Red Diamonds from Lucent Diamonds Inc.
Using a multi-step process, Lucent Diamonds has developed a new treatment process for certain natural diamonds that creates colors from pink-purple through red to orangy brown.
A Crystallographic Analysis of the Tavernier Blue Diamond
This study uses both historical information and modern data to create a computer model of the Tavernier Blue, orienting the finished diamond within the original diamond crystal.
The “Type” Classification System of Diamonds and Its Importance in Gemology
Knowledge of type allows gemologists to better evaluate if a diamond might be treated or synthetic, and whether it should be sent to a laboratory for testing.
Abstracts; Fall 1991
This article, from the Fall 1991 issue of Gems & Gemology, is a compilation of abstracts of important gemology-related articles published outside of Gems & Gemology.