About Garnet – Demantoid

The Demantoid Garnet is one of the most brilliant, fiery, gemstones ever found. Demantoid is part of the Garnet group. After its discovery in 1868 in Russia’s Ural mountains, the Demantoid rapidly proceeded to become a much desired gemstone. Comet-like, it scintillated among the finest jeweler’s workshops in Paris, New York and St. Petersburg. First and foremost, Russia’s star jeweler Carl Fabergé adored it for its tremendous brilliance and loved to incorporate it in his precious objects. While Demantoid has been extremely rare, in the middle of the 1990s, a new seam bearing gemstones was discovered in Namibia. Demantoid was among them. The story of that discovery is fascinating. It is set in Namibia Africa. In this vast, steppe-like country baked in the African sun, there lay the ‘black mountains’ blurred in the bluish haze. It’s a dry, hard country. Yet for a long, time it had held an unknown treasure: gemstones! Millions of years before, liquid magma had shot up from the the Earth and solidified shortly before it reached the surface. In the course of time, the wind and the elements removed the surface strata until finally only the distinctive granite mountain, the Spitzkoppe, was left. No-one realized that in these mountains were hidden one of the most rare and sought after of all gemstones. It wasn’t until in December 1996 and quite by accident, a wandering goatherd found a number of crystal-like objects which seemed to him kind of interesting. After showing them around in the village, the attention of experts was drawn to the find, and they quickly realized what a treasure was being presented to them.

The reason that we refer to Garnet as a group is that all species of Garnets possess similar physical properties and crystal form, but differ in chemical composition. The different species are Pyrope, Almandine, Spessartine, Grossular – (varieties of which are Hessonite and Tsavorite), Uvarovite and Andradite. The last two, up until recently have been quite obscure, except among collectors and gemstone lovers. Strictly speaking it is a green Garnet, or rather the star of the green Garnets. Not without reason does it bear a name which means ‘Diamond-like’. The name comes from the Dutch and makes reference to the outstanding quality of this gem, its incomparable brilliance and fire. Some gemstone lovers claim that a Demantoid will continue to glow even in the shade.

The Demantoid Garnet is actually the green variety of the Garnet mineral Andradite. But it is more than that: it is the most expensive of Garnets and one of the most precious of all gemstones. It is highly esteemed on account of its rarity coupled with that incredible luminosity. The reason for this is that Demantoid has an extremely high refraction (refractive index 1.880 to 1.889). Yet its high dispersion is also remarkable, in other words its ability to split the light which comes in through the facets and break it down into all the colors of the rainbow. The Demantoid is a master of this in a similar way to that of a Diamond.

The spectrum of its colors includes many shades of green, from a slightly yellowish green to a brownish green with a golden glow. Particularly precious is a deep ‘Emerald Green’, though this only occurs very rarely indeed. It is not only fine and unusual, but the specimens are also mostly small, large ones being extremely rare. Once cut, only a few stones weigh more than two carats, and most of them hardly exceed one. And even if you come across one set in a piece of jewelry, it is often likely to be a small stone.

Sources for Demantoid Garnets include, Russia, Korea, Congo, Namibia and Madagascar.