Carico Lake is the marketing name for turquoise from the Aurora claim located in Carico Lake Valley Nevada. The story is told in Turquoise in America Part Two, 1910-1990
 
This cabochon weighs 4.7 carats and measures 1.75cmin diameter X 7mm.and is priced at $15 a carat or $70. It is not treated and is backed. I have assigned a TG of 80 or HG. This stone comes from the Nevadagem Collection. White spot is camera flash.