| The demantoid is one of the most brilliant gemstones that exist, yet until recently it was little known 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 belongs to the large gemstone family of the garnets, and is actually a variety of the garnet mineral andradite. But it is more than that: it is the most expensive kind of garnet and one of the most precious of all gemstones. It is highly esteemed on account of its rarity coupled with that incredible luminosity. For the latter, at least, there is a plausible explanation: the 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 colours of the rainbow. The demantoid is a master of this, and does it even better than the diamond. The spectrum of its colours 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 jewellery, it is always likely to be a small stone. |
.jpg "Demantoid Garnet 1.93ct 7.5mm x 4.6mm, Moderately Included Round")
