Tanzanite. Mineral Composition: Calcium, Aluminium, and Hydroxyl sorosilicate Value: $600 to $1,000 per carat.

Tanzanite is a blue-violet variation of the mineral Zoisite. This rare crystal is only mined in one place in the world, the Merelani Hills of Northern Tanzania. Tanzanite was discovered in 1967 by a Masai tribesman who found a cluster of highly transparent, intense violet-to-blue crystals. The Masai tribesman told local fortune hunter Manuel d’Souza what he had found and d’Souza initially thought that it was a new deposit of sapphires.
After the initial discovery of this first cluster of Tanzanite, more reports came in that other similar crystals were found in a 20-square mile area. Tiffany & Company dubbed this newly discovered crystal Tanzanite, after its home country, and marketed it as a rare gemstone.