Tanzanite - A Gemstone Found Nowhere Else on Earth

Tanzanite, a blue-violet variety of the mineral zoisite, has only ever been found in commercial quantities in a roughly two-square-kilometer area near the Merelani Hills at the foot of Mount Kilimanjaro, since its discovery in 1967. This makes it one of the rarest gemstones in the world, limited to a single small deposit.