A look at the history of color types such as "pigeon's blood" and the difficulties in standardizing these definitions.
Gem Color Types: History and Challenges with Lotus Gemology's Billie Hughes
From early times, humans have compared the color of rare gemstones to that of more common phenomena or objects in an attempt to communicate their appearance. In this presentation, Billie Hughes retraces the history of these terms, from the Hindu Puranas, to blue-white diamonds, to the padparadscha sapphire and pigeon's blood ruby. Developing a comprehensive colored stone grading system has been the dream of gemologists since the late 1970's, but despite a number of valient attempts, we are no closer to the goal today than we were four decades ago. This presentation examines the various problems of colored stone grading, explaining why the challenges are at least an order of magnitude greater than the grading of diamonds.
When
Monday, 4th February 2019, 13:00–14:00
Where
Gemstone Industry-Laboratory Conference (GILC): By invitation only
AGTA Gemfair, Tucson Convention Center
Tucson, AZ (USA)