What is the composition/hardness of Tanzanite?
Tanzanite is a hydrous Calcium-Aluminum Silicate with a hardness of 6.5 – 7 on the Mohs scale. This means that Tanzanite’s hardness is similar to emerald but a bit less brittle and should be cared for. It is not as hard as diamond which rates as 10 or sapphire which rates as 9 on the Mohs scale but harder than steel which rates about 4-5. Therefore Tanzanite should not be worn during activities that may cause impact. Ideally it is set as a necklace, dress ring, earrings or occasionally a bracelet.
