Tanzanite is rare. In fact this beautiful blue violet gem is beyond rare. With just an estimated 30 years of supply remaining in the mine, as time passes Tanzanite becomes ever more precious.
Tanzanite is found in only one place on earth, deep in the foothills of Mount Kilimanjaro in Tanzania, East Africa. The entire area mined is only four square kilometres wide. Intense geological research has shown Tanzanite’s geology to be totally unique. The chance of it occurring outside the current production area (and its immediate vicinity) is less than a million to one.
So Tanzanite is rare in both a gemmological and geographic sense. In fact, its single source and limited supply makes it at least one thousand times rarer than a diamond.
Spinel’s history is a royal one, with some large stones adorning the finest of crowns.
- The 14th century Black Prince, 170ct piece set into the State Crown ( The Crown Jewels).
- The Samarian Spinel, one of the largest, 500ct and is set into the Iranian Crown Jewels.
- The Imperial Crown of Russia, the magnificent 400ct uncut stone is set with 11,000 diamonds.
- The Timur Ruby, 361c of unfaceted polished spinel is set into a necklace and was given to Queen Victoria. It is also part of the Crown jewels.
Spinel comes in a variety of colours, mainly blue, green, yellow, brown, black, & orange, with the reds & hot pinks being the most highly prized.
As Spinel & ruby were often found together in mineral deposits it was presumed that they were the same, but in 1783 Spinel was found to be a different mineral to that of ruby, hence ” The Science Of Gemmology Was Born “. As both stones are coloured by chromium the visual look is similar but the structures are quite different.
Spinel is singly refractive and has a hardness of 8 whereas Ruby is doubly refractive and has a hardness of 9. Spinel being the rarer of the two. It is also one of the few stones that doesn’t necessary improve with heating .