Article Search Results

Show Filters
Showing 14 results for "*"
Article
Fall 2015 G&G: Trapiche Emeralds, Synthetic Diamonds and a Large Diamond Source

G&G Brief presents an overview of the content of the Fall 2015 issue of Gems & Gemology.

Read More

Optical Defects in Diamond: A Quick Reference Chart

A simple chart on optical defects in diamond, including those that produce coloration and fluorescence colors.

Read More

Hydrogen-rich Diamonds
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.

Read More

Calcium Fluoride Coating Found on 13 "Fancy" Pink Diamonds

Recent lab examination reveals that traditional treatments such as calcium fluoride coating are still prevalent in the trade, and great care must be taken to identify them.

Read More

Confusing, Triangular Inclusions in an Art Deco-Style Pin
Spring 1991 G&G Lab Notes

This section, from the Spring 1991 issue of Gems & Gemology, is a compilation of interesting finds from GIA’s laboratories.

Read More

Treated Green Diamonds
Detection of Treatment in Two Unusual Green Diamonds

A pair of sharp absorption bands in the near-infrared region, referred to as H1b and H1c, have been detected in one (and the H1b band in the other) of two green diamonds known to have been treated.

Read More

The Identification of Artificial Coloration in Diamond

The source of color in some diamonds, particularly fluorescent green and some yellow stones, can be very difficult to identify despite increasing knowledge about the radiation-related bands seen in the visible spectra of diamonds.

Read More

Characterization and Grading of Natural-Color Yellow Diamonds

A large number of natural-color yellow diamonds are analyzed using grading and appearance aspects among other characteristics to clarify the differences between them and the light yellow diamonds associated with GIA's D-to-Z color grading scale.

Read More

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.

Read More

Lab-Grown Colored Diamonds from Chatham Created Gems

This article compares some of Chatham Created Gems’ synthetic colored diamonds to natural diamonds and explains the results.

Read More