Description : Demantoid belongs to the andradite variety of garnet. Garnet have been a really successful gemstone for years. Which is due to his brilliance, it also has quite a unique purity of color, since it’s one of the only gemstone to have a singly refrective (some other gems with the same effect are the spinel and diamond). Garnet is often seen as a common gemstone. But even if there is some common and inexpensive garnets such as almandine. There is also quite opposite for other garnet. such as spessartite, tsavorite and Demantoid. When we cut the gems, we need to take care that the horsetail is good because it is what make the beauty of the stone. The craftmen need to be really careful to get the beauty out of the stone. (shown above).
Charasteristic : On the Moth scale it is at 7 to 7.5, it also what make the Demantoid so unique.
Where? : The Bobrovka and Chusovaya River regions of Russia’s Ural Montains. Other sources include Namibia, Iran and Italy. The most important mining source are Russia and Namibia.
History : Even if garnet has been know for a very long time, the demantoid variety on the other hand was only discovered in 1868 in Russia’s western central Ural Mountains. The site was about 110 kilometers from Ekaterinburg, along the Bobrovka River, near the village of Elizavetinskoye. The story is the “Miners were immediately stunned by the highly refractive nature of the gem material, which is atypical for garnet.
Name : Demantoid, mean “diamond-like luster”, but the word is made up of the French word demand, which mean “diamond”. They decide to called it like that because of it’s luster and brilliance similar to diamond.
Appearance : Demantoid is the green variety of andradite garnet, Demantoid is often and primarily green. But the exact shade ranges from a strong yellowish green to emerald. Some have a brownish cash, with is due to the iron in the ground, which intoxicated some of the gemstone. But also make them quite unique. Its dispersion (0.057) is unusually high, and this is often visible as “fire” (rainbow-coloured flashes of light), although in some cases the stone’s green body colour can render this effect less noticeable. Their luster is adamantine. Demantoid also has a high refractive index of 1.80 to 1.89.
Horsetail : Russian demantoid often contain inclusions of chrysotile,which is a type of asbestos. These fibers radiate out from a very small crystal of chromite. These inclusions are feathery golden threads that tend to curve and resemble the tail of a horse, and are therefore referred to as horsetail inclusions. In gemology, the presence of such inclusions is regarded as ‘diagnostic’ for natural demantoid (i.e. these inclusions are not found in any other green gemstone). Some gemstones are more valuable for their inclusions, and ‘horsetails’ can be regarded as desirable features in demantoid, as they are taken as an indication of prestigious Russian origin, although some demantoids from certain other locations (such as Italy and Iran) may also contain ‘horsetails’, which are regarded as being characteristic of a serpentinite geographic origin, and, on the other hand, not all Russian demantoids actually contain ‘horsetails’. The microstructure of some demantoids is believed to be affected by the presence of ‘horsetails’ (the ‘horsetail’ typically originates towards the centre of the nodule, with the fibres branching out and radiating towards the surface), whereas horsetail-free demantoids from other sources frequently display flat crystal faces.
Find us : Find our Demantoid Garnet on our Etsy page.
Youtube: Where we show our stone and give info.