Tanzanite! The first thing you notice is the color: Deep, vivid blue, with a purplish tinge that dances about the stone as it moves in the light This modern gemstone was unknown until 1967, when Massai herdsmen in eastern Africa noticed blue crystals sparkling in the sun. In 2002, the American Gem Trade Association named Tanzanite an alternative gem to celebrate December births. Tanzanite is a member of the Zoisite family of gems. Hardness: 6-7.