Chrysocolla has 2 meanings in the gem trade.
1. A mineral species, prized for its intense blue to blue-green colors with a Mohs hardness of 2.5 to 3.5.
2. An aggregate (rock) composed mainly of chrysocolla but containing other minerals.
“Chrysocolla” has also been used as a misnomer for chrysocolla chalcedony (chalcedony intergrown with chrysocolla or colored by minute chrysocolla inclusions).
High-grade chrysocolla chalcedony like the material in this carving is called “chrysocolla gem silica” or simply “gem silica” and has a Mohs hardness of 6.5–7.
Chrysocolla may be found wherever large copper deposits occur, including Chile, Peru, Mexico, Russia, Taiwan, Indonesia, and the Southwestern United States. The finest chrysocolla gem silica has come from Arizona.
Modern mechanized copper mining is preventing the extraction of chrysocolla gem silica when a pocket is discovered, so it has become rare. As a result, it is the highest priced chalcedony.
Semi-transparent gem silica with a high clarity and even color can retail for as much as $200–$300/carat. On the other hand, semi-opaque chrysocolla aggregate stones are available for costume jewelry prices. They can be attractive and ideal for designer jewelry.
Many stones sold as chrysocolla chalcedony are dyed chalcedony. “Gems & Gemology” discussed their identification in the spring 2020 issue (pp 188-190) and fall 2006 issue (p 140). Raman spectroscopy and UV Vis-NIR spectroscopy were used to detect dyed stones. Deal with reputable sellers when buying chrysocolla chalcedony.
Glenn photographed this carving and let me use the photo in my “Rare Gemstones” book. www.reneenewman.com/raregems.htm
You can see more of Glenn’s impressive carvings on his website: www.lehrerdesigns.com
Guest articles by Renée Newman:
https://gem-spectrum.com/category/renee-newman
About the author:
Renée Newman is a gemologist (GG, GIA), lecturer, writer and author of 15 books on gems and jewelry. Her goal is to provide consumers and jewelry professionals with unbiased, affordable information on how to buy, evaluate and appreciate gems and jewelry. She can be reached through her website:
