Carico Lake turquoise is named after the location of its mines on a dried up lake bed in a high, cool area of Lander County, Nevada. Its clear, iridescent, spring green color is due to its zinc content and is highly unique and collectible. Carico Lake turquoise is also found in a dark blue-green color with a black or brown, spider web matrix. The less common lime green turquoise which is suspect to actually be predominately faustite, is very valuable due to it scarcity and demand. It is hard material. This mine is also known to produce rare psuedomorph clams that are filled with turquoise. This Gem High-Grade Carico Lake Natural Turquoise Cabochon is partially backed and weighs 17.2 Ct. Measures approximately 21.1 mm, by 14.8 mm, by 6.4 mm Free Shipping