Gems & Gemology’s 7 Most Unusual Encounters from 2019
Check out some of the most interesting and unusual diamonds and coloured stones submitted to GIA’s laboratories in 2019.
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.
Treated-Colour 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 colours from pink-purple to red to orangey brown.
Spring 1991 G&G Lab Notes
This section, from the Spring 1991 issue of Gems & Gemmology, is a compilation of interesting finds from GIA’s laboratories.
“Fluorescence Cage”: Visual Identification of HPHT-Treated Type I Diamonds
HPHT-treated type I diamonds of various colours may exhibit unusually intense fluorescence at the facet edges and junctions.
Grey-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 coloured grey to blue to violet.