Bisbee turquoise is one of the most famous of all turquoise. It is a byproduct from the Phelps Dodge Lavender Pit copper mine in Bisbee Arizona. The story of Bisbee is found in Turquoise in America Part Two, 1910-1990.
 
This cabochon weighs 28.6 carat and measures 2.5cm X 2.25cm X 4mm. It is priced at $100/ct or $2860. It is not treated and is backed. It is considered Smoky Bisbee I have assigned a TG of 90 or VHG. I purchased this stone from Bruce Mead who cut the stone. White spot is camera flash.