Tanzanite was first discovered relatively recently in 1967 when Masai tribesmen found a cluster of crystals in the Merelani Hills in north east Tanzania near Mount Kilimanjaro, an area that remains the only known location for this beautiful gem.
It is not one of the harder stones and has a tendency to brittleness so care needs to be taken, particularly when set as a ring but its beauty and rarity make it highly prized.
The best stones exhibit a strong blue colour with a violet tint and a bright lively appearance. They are strongly pleochroic which means they exhibit different colours in different directions through the crystals. An untreated stone will typically show blue, pinky-violet and yellow.
Most stones on the market today have been heated to turn them from brown to blue with the best colours being seen in larger stones where the colour is most intense and displayed to best effect.
Description: Tanzanite is the transparent purplish blue variety of the mineral Zoisite, it is found only in Tanzania (hence the name).
Hardness: 6.5 – 7 on Mohs Scale