This most attractive gemstone is found in just one place in the World. Tanzania in East Africa had previously been known more for its wildlife than its minerals, but that all changed in the early 1960s. Tanzanite is a silicate (calcium aluminum) and was found in the 1960s. Its rich blue color has made it “the gemstone” of the 20th Century as far as the industry is concerned.
Its promotion by the jewelers of the USA has meant it is a highly prized gemstone which can be cut into a whole variety of different shapes by experts. It is not a particularly hard gemstone so it must be treated with extreme care, especially during cutting and as a result is usually set in earrings and necklaces.
Tanzanite, a member of the zoisite family, was discovered by accident near the Mererani Hills close to Arusha, the gateway to Tanzania’s wildlife parks. That was less than half a century ago.
The Masai herdsmen who found the sparkling stones did not value them but they picked them up anyway and when they were shown around, others knew of their potential value.
Many gemstones date back to ancient times and while one of the theories of the origins of Man puts early Man in East Africa, few in the world outside the East Africa had seen this type of gemstone before.
Its discovery led to the setting up of a series of small mines around Merelani and the trading in tanzanite seems to be well organized and totally legitimate with 90% of these licensed traders members of the International Colored Gemstone Association (ICA). Over two million carats were mined in the first five years after Tanzanite was discovered. It is thought that there is about 20 years of deposits left still to mine and hence the value of associated with this wonderful gemstone.
The Tanzanian Government took control of the situation with the aim of ensuring the stones were not exported in a raw state. Historical licenses were revoked and the area divided into four blocks for mining. One of those blocks is very professionally mined by a publicly traded South African concern, but the other four are by artisan miners and a local businessmen consortium. That publicly traded company Tanzanite One Group not only mines tanzanite but also buys from the artisans.
The result has been an annual income to the country of over $20 million with the US being the major customer. In the US, the annual market in jewelry made from tanzanite is estimated to be around $500m.
Types of Zoisite
Tanzanite is a deep blue on color, some of the larger carats being particularly impressive because of the purple tinge surrounding the deep blue. The blue itself can range from light violet blue to very deep blue. This is in contrast to its reddish brown appearance in its raw state. It is heat treatment which produces its vivid blue color and extreme care needs to be taken in this treatment as it is a most valuable gemstone.
The immediate region has several different gemstone deposits. Tanzanite is blue zoisite. The region also has pink, yellow and green zoisite but none compare with the blue, Tanzanite.
Properties of Tanzanite
Fracture Uneven to conchoidal
Mohs scale 6.5 – 7
Specific gravity 3.10 – 3.38
Tanzanite is rare and has become a most prized gemstone for jewelry of all kinds. Its rich blue color added to its rarity has meant that fans of colored gemstones the world over want a tanzanite piece in their jewelry boxes.
It can be cut into many different shapes, the classical cuts and more imaginative modern designs as well.
It is rare that a new gemstone comes on to the market but tanzanite did it with quite an impact. There is just a single source of the stone in the world hence its value is tends to hold and the demand for tanzanite jewelry is expected to remain high. If you are looking for elegance and have the financial wherewithal to pull it off then Tanzanite is the stone for you.