Tanzanite is the blue to violet gem variety of the mineral Zoisite (a calcium aluminium hydroxyl sorosilicate) belonging to the epidote group. It was discovered in 1967, in the Merelani Hills (Mererani) of the Manyara Region in Northern Tanzania, near the city of Arusha and Mount Kilimanjaro. Tanzanite is used as a gemstone and naturally formed Tanzanite is extremely rare and is still only found in the Mererani Hills.