Tanzanite is a variety of Zoisite (calcium aluminum silicate ) and has a colour varying from blue to violet. This stone is Heat treatments enhance the Tanzanite’s colours. This gemstone is named “Tanzanite” because a deposit was found in 1967 in Tanzania, East African country. Tanzanite is distinguished by a perfect cleavage (it cleaves “without leaving any rough surfaces; a full, smooth plane is formed where the crystal broke”). Besides, Tanzanite is only found in Tanzania, East Africa.