Tanzanite is a rare gem variety of the mineral zoisite, found in only one location in the world in Tanzania, it has a hardness of 6-6.5 on the Mohs scale. This stunning piece Tanzanite Facet Rough weighs 9.79 cts. Measures 9X9X7mm and is clean. This piece will cut and exquisite gemstone or make an amazing carving.