Found exclusively in the country of Tanzania (hence, the name!), near the Merelani Hills, Tanzanite was first discovered by a Maasai tribesman in 1967 who at first thought he had stumbled upon a Sapphire deposit. But in fact, he had found a stunning, unique type of purple/ blue Zoisite which was renamed by Tiffany & Co., the first company to use the stone in high jewellery. According to a Tanzanian geologist, the unique circumstances which sparked the formation makes it highly unlikely that a new Tanzanite deposit will be found anywhere else in the world, making them a thousand times more rare than Diamonds. At the current rate of mining, it is likely that the available supply will be depleted in this generation.
Most Tanzanite is trichroic, appearing either blue, violet, or burgundy depending upon the direction of light being reflected from the stone. This phenomenon complicates the cutting process, making it imperative that the best gem cutters are employed to bring out the full potential of the rough. Most gem quality Tanzanite in the marketplace is heated to give a deep, strong saturation though occasionally some paler but equally stunning unheated material becomes available.
Tanzanite rates 6.5 – 7 on the Moh’s scale, which means that it is suitable for most everyday jewellery, although necklaces and earrings would be best. Due to the way Tanzanite crystals form, there is an availability of good sized stones, in sizes above 3 carats.