Bisbee is the favorite turquoise for many. The story of Bisbee is told in Turquoise in America Part Two 1910-1990. This cab comes from Jackson Clark who bought it from Bob Mathews.
 
This cabochon weighs 3.8 carats and measures 1.5cm X 1cm. It is not treated and backed. It is priced at $150 a carat or $570. I have assigned a TG of 89 or VHG Very High Grade. Bisbee of this grade is exceptionally rare and seldom found in the market.