This cabochon of Chrysocolla is from Sonora Sunrise in Mexico. There is a small amount of Cuperite at the top. Chrysocolla is a copper bearing mineral found wherever copper deposits occur especially in areas of the southwestern USA, Chili, Zaire, Australia, France and England. Pure chrysocolla is too soft for jewelry purposes but it is often found in quartz deposits which makes it hard enough to polish for cabochons. It is often found mixed with malachite, turquoise and azurite.   
Flat polished beveled back
Measures 19.65x38.20mm
Thickness 5.65mm