DEMANTOID – THE ‘DIAMOND-LIKE’ GEMSTON WITH INCOMPARABLE LUMINOSITY
Its name derives from the Dutch language, translated as ‘diamond-like’ which refers to the outstanding qualities of the green garnet, primarily its brilliance and fire, hence the name given to it to by connoisseurs and lovers of gemstones, namely ‘the star of garnets’.
Demantoid is amongst the most precious gemstones hitherto discovered on earth. Belonging to the large family of garnets, it is a variety of the mineral ‘andradite’, but cherished far beyond a simple member of the garnet family. Demantoid is highly esteemed on account of its rarity and incomparable luminosity. It has extremely high refraction complemented by remarkable dispersion, which is the ability to split the incoming light and to break it down into fascinating colors of the rainbow. Some sources have placed demantoid before diamond with respect to light dispersion.
Demantoid displays different nuances of green, ranging from a slightly yellowish to a brownish green, with an enchanting golden glow. The deep emerald green variety of demantoid is esteemed as the most precious and the rarest of all other shades.
FAVORITE STONE OF RUSSIA’S STAR JEWELER
Discovered in 1868 in Russia’s Ural Mountains, the demantoid became a desired gemstone within a very short period of time. The jeweler’s workshops in Paris, New York and St Petersburg welcomed the newly discovered vivacious gemstone, but first and foremost Russia’s star jeweler Carl Faberge admired and praised the green gemstone for its exceptional brilliance and incorporated it in his artistic creations.
This popularity was disrupted by the outbreak of World War I, which made the appearance of the highly praised green gemstone increasingly rare, to the extent that only the remnant stocks of the gemstone’s original source in the Ural Mountains were to be seen.
Meanwhile, demantoids which were discovered in Congo and Korea in 1975 were found inferior in quality to the mines of Ural Mountains. The discovery of new gemstones in Nambia in the mid-1990′s, amongst which a variety of demantoid was found, meant a renaissance for the star of green garnets.
The story of that discovery resembles a fairy tale! This is a vast and steppe-like country, which surrenders to the burning African sun. Far away in the ‘black mountains’ of this hard and dry territory, there had been an unknown treasure of gemstones for millions of years, during which significant changes had occurred; the wind and other elements had removed the surface strata, leaving only the distinctive granite mountain, called the Spitzkoppe, and the gemstones it concealed.
In December 1996, a wandering goat-herd encountered by mere coincidence, a few crystal-like objects which appeared worthy of attention. Only the experts in the nearby village could recognize the treasure being presented to them.
In the meantime, the Namibian government has issued concessions for gemstone mines. The rare gemstones are carefully quarried by hand from the parent rocks and measures have been taken to minimize the loss when handling the precious raw material.
HORSETAIL INCLUSIONS:DEMANTOID’s HALLMARK
Demantoids from Namibia come in shades ranging from a vivacious light green to an intense blue-green, all of which display remarkable brilliance and have a hardness of slightly below 7 on Mohs’ scale, rendering them appropriate for jewelry. However, they are void of one important feature unique to the genuine demantoid on the basis of which the authentic gemstone has always been identified through the microscope, namely the ‘horsetail inclusions’.
These golden brown crystal threads of chrysotile, radiating from the center of the stone, whose resemblance to the tail of a horse is unmistakable, clearly visible in demantoids from the Ural Mountains, were missing in the relatively inclusion-free gems from Namibia. These horsetail inclusions were not only typical of the demantoid; they could even enhance its value if they were pronounced. As surprising as it may sound, and although inclusions as a rule can impair the transparency of a gemstone, the demantoid’s ‘horsetail inclusions’ if well formed, can increase the price of the gemstone considerably!
This ‘fingerprint of Nature’ is the hallmark which proves the authenticity of one of the rarest and most valuable gemstones on earth. This rarity will also determine the price, since a demantoid from the Ural Mountains of Russia will be appraised much more highly than a green garnet from Namibia, irrespective of the latter’s brilliance!