Tanzanite – A unique stone with an unusual toned aura, this natural gemstone only occurs in East Africa’s Tanzania, hence the name. Discovered only in 1967, this blue zoisite has become increasingly popular, so much so that it has staked its claim to fame on December’s birthstone list. Tanzanite ranges from a delicate blue (most rare) to a rich blue violet tone with rich purple overtones. The natural raw crystal formations of Tanzanite often display brown and yellow hues.