Tanzanites

Found in one place on earth — a few square kilometres in the Merelani hills of Tanzania — and nowhere else since its discovery in 1967. Tanzanite is the blue-violet variety of zoisite, and it is trichroic, so a single crystal shows blue, violet and burgundy depending how you turn it. Ours range from vivid blue to violet-blue, with a bluish-green zoisite from Tanzania beside them. Viewings are by appointment in Kuwait City.