Tanzanite

Birthstone for December

Tanzanite is one of the rarest gemstones on Earth — found in only one place, a five-square-mile area near Mount Kilimanjaro in Tanzania. Discovered in 1967, it is a blue-violet variety of the mineral zoisite, and its color shifts between blue and purple depending on the angle and lighting. Tiffany & Co. named the stone 'tanzanite' and introduced it to the market in 1968, making it one of the few gemstones to receive a major commercial launch in modern history. Geologists estimate that the single known deposit will be exhausted within a generation, which gives tanzanite a scarcity that no marketing campaign could manufacture.