Gemstone of the 20 century: tanzanite
16.04.16
Tanzanite is the most exciting gemmological find of the 20th century. It is also one of the rarest gemstones, as it occurs in only one place on earth – Tanzania, near majestic Mount Kilimanjaro in East Africa.
When discovered in 1967, Tanzanite was celebrated as the 'gemstone of the 20th century'. Shortly after its discovery, it was offered to Tiffany & Co, who named the gemstone and introduced it to the world.
Tanzanite is a crystalline gemstone variety of the mineral zoisite. It is made from calcium, aluminum and silica. Its colour scale varies from blue, similar to sapphire colour, to more violet and purple shades. Its hardness is similar to emerald, which is not as hard as diamond or sapphire but harder than steel.
Tanzanite is mined within a labyrinth of complex folds underneath the earth's surface - in the foothills of Kilimanjaro, the area which covers only four square kilometres.
For this reason, tanzanite is extremely rare. In fact, the gemstone is considered to be a thousand times rarer than diamond due to its unique formation. The chance of it occurring outside the current production area has been estimated as less than a million to one.
Interestingly, the gemstone can change colours when viewed in different crystal directions. This ability is known as pleochroism. This enables cutters to have some control over the hue, which depends on how they cut the rough stone.
Blue stones with a surrounding hint of purple are valued the most. A natural perfectly shaped stone of this colour can command extremely high prices, sometimes approaching that of diamonds.
Tanzanite can also be synthetically created. Yet, the stone no longer has the properties of zoisite. Instead, it becomes more of the mineral called fosterite.
When the first stones were discovered by Maasai tribesmen, they had just survived a bush fire, which had heated the rough tanzanite and changed it into the stunning intense blue colour. Therefore, modern natural and synthetic tanzanite stones are still being heated for colour enhancement.
In terms of its spiritual properties, tanzanite is one of the most valuable of all metaphysical crystals for spiritual exploration. It is a very protective stone, sometimes referred to as the “workaholic’s stone”, because it helps to relieve stress and depression, transmute negativity, enhance poise, composure and harmony.
