Carico Lake is the marketing name for turquoise from the Aurora claim located in Carico Lake Nevada. The story is told in Turquoise in America Part Two, 1910-1990
 
This cabochon weighs 40.6 carats and measures 3.5cm X 2cm X 8mm.and is priced at $20 a carat or $812. It is not treated and is backed. I have assigned a TG of 86 or VHG. This stone comes from the Nevadagem Collection. White spot is camera flash.