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.
Irradiated Topaz and Radioactivity
Large quantities of colorless topaz are currently being treated by gamma irradiation to turn them blue.
An Update on Color in Gems. Part 1: Introduction and Colors Caused by Dispersed Metal Ions
This three-part series of articles reviews our current understanding of gemstone coloration.
An Introduction to Gem Treatments
A guide describing frequently encountered gem treatment processes, their detection, and special care tips for treated gems.
Color In Gems: The New Technologies
A discussion of work being done to enhance color in gemstones, as well as techniques used at the California Institute of Technology to detect whether colors are natural or enhanced.
Dual-Color Double Stars in Ruby, Sapphire, and Quartz: Cause and Historical Account
Examines a form of asterism comprising two six-rayed stars, one white and one that exhibits the stone’s bodycolor. Firsthand accounts and a survey of patent documents reveal that diffusion has been used to create or enhance this optical phenomenon in synthetic and possibly natural corundum since the 1950s.
Abstracts; Spring 1991
This article, from the Spring 1991 issue of Gems & Gemology, is a compilation of abstracts of important gemology-related articles published outside of Gems & Gemology.
Abstracts; Summer 1991
From the Summer 1991 issue of Gems & Gemology, a summary of important gemology-related articles published in other journals.
Orangy Pink Coated "Soft Coral"
A coral specimen that was coated—not dyed—with a coloring agent only on the surface, an unusual method evidenced by microscopic features.
The authors have encountered hundreds of polymer-filled aquamarines in the Chinese jewelry market.