Monday, January 26, 2009

The colourful world of the garnets


The specialist world was amazed a few years ago by the fantastic find of a type of garnet which had been very scarce until then. At the Kunene River, on the border between Namibia and Angola, a deposit of radiant orange to red 'spessartites' was discovered. The spessartite was originally named after the site of a find made in Germany. Spessartites had led a quiet, shadowy existence as stones for gemstone lovers and collectors until that momentous discovery in Namibia. There were hardly any used in jewellery because they were so very rare. But this new find changed the gemstone world. Since then, its wealth has increased by the addition of this unusually fine, intensely radiant orange-red gemstone. Under the trade name 'mandarine-garnet', this wonderfully orange noble garnet became world-famous in no time at all. Unfortunately, the mine in the quiet hills of Namibia was only able to be exploited for a few years. The search for gemstones in the remote bush country began to involve too much effort and became too expensive. So fears grew that this highly precious gemstone, which had shot into the firmament of the gemmological world like a rocket, might only become available in rare individual cases from the stocks of a few cutting-centres. That is, until another deposit of the orange treasures was discovered, this time in Nigeria. Their colour and brilliance are so similar to those of the mandarin garnets from Namibia that only an experienced specialist can discern the subtle differences.Now for the green garnets. Green garnets?! Is there really such a thing? Indeed there is! In fact, several green varieties are known. First there is 'grossularite', created by Nature in many fine tones of yellow, green and brown and esteemed for its many fine interim hues and earth colours. Here too, there was a spectacular find: in the final year of the 20th century, extensive grossularite deposits were discovered in Mali. These Mali garnets captivate us with their great brilliance. Even the brown, which is otherwise not terribly popular, seems vivid and natural, and goes particularly well with ethnologically inspired trends.Probably the best known green garnet is the tsavorite or tsavolite, which also belongs to the grossularite group. Tiffany's in New York gave this name to the previous emerald-green stone which was discovered in 1967 by a British geologist, Campbell R. Bridges, in the north-east of Tanzania - after the place where the discovery was made, near the Tsavo National Park with its wealth of game. The green of the tsavorite runs from vivid and light to deep and velvety and, like all garnets, it has particularly good brilliance.The star of green garnets is the rare demantoid, a gemstone for connoisseurs and gemstone lovers. Its brilliance is positively tremendous, even greater than that of the diamond. Russia's star jeweller Carl Fabergé loved the brilliant green garnet from the Urals more than anything else, and used it in his creations. Meanwhile, the demantoid is no longer quite as scarce in the gemstone trade, thanks to some new finds in Namibia. Demantoids from Namibia are of good colour and brilliance, but they lack one tiny feature: the so-called 'horse-tail inclusions'. These fine, bushy inclusions are the unmistakable, typical feature by which a Russian demantoid is recognised.

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