Tanzanite is a bluish purple gemstone that is found only in Tanzania, the
East African nation from where the stone also takes its name. Found in 1967 and
introduced to the world two years later in 1969, Tanzanite is a relatively new
stone. But its popularity has increased by leaps and bounds since it was found,
and today tanzanite occupies a distinguished position in the gemstone market.
Tanzanite is considered a very valuable stone because of its rarity. It has a hardness of 6-6.5 on the Mohr’s scale and a density of 3-3.5. It has an orthorhombic crystal structure. It rarely occurs in a pure blue shade, it almost always has a touch of violet. In larger sizes, tanzanite displays a deeper blue, while, in smaller sizes, it displays a lighter shade akin to lavender. At times, tanzanite also can also be found in a pre-dominantly greenish shade. It also displays brownish hues at times.
Tanzanite should not be mistaken for sapphire and vice versa. Sapphires are purely blue; they do not display multiple shades. In fact, it is this property of displaying multiple hues from different directions that makes tanzanite a special gemstone. This property of displaying different shades from different angles is called pleochroism. Natural tanzanite is not bluish; it is predominantly brown or bronze. It is only after heating that it gains its violet or blue color.
Tanzanite in jewelry.It is more prudent to buy tanzanite loose, instead of buying it pre-set in a piece of jewelry. Buying the stone loose gives you more control over its use and setting. When selling a loose stone, the sellers are also unable to dupe the customer as whatever they are selling is conspicuously placed in front of the buyer, unhidden by any strategic pre-setting.
Tanzanite is best set in a jewelry piece as the central stone along with smaller stones on the border. A big size tanzanite can also be used as the only stone in jewelry items such as rings, earrings, pendants, bracelets, etc. Tanzanite is most preferred in oval, heart, round and cushion cuts, as in these cuts, its trichroic properties become visibly pronounced.