One of the rarest types of garnet, demantoid garnet is gemological name used for green andradite garnets. First discovered in 1868 in Russia, green demantoids were given there name because of their diamond-like brilliance and fire. The high refractive index and dispersion of andradite does give these garnets a remarkably diamond-like appearance. The green color comes from trace amounts of chromium. In the 1990’s demantoid garnets were discovered in Namibia. While the greens from Namibia aren’t as intense as the Russian stones, the gems tend to be cleaner, so the brilliance and fire shows very strongly. Most demantoids tend to be small, so larger stones over one carat are uncommon.
This demantoid garnet is a beautiful yellow-green color and it has lovely dispersion that can’t be captured in this photo–making it reminiscent of a colored diamond. The garnet is faceted in a modified version of the classic diamond round brilliant design cut to “hearts and arrows” precision, creating a brilliant and dispersive gemstone. It weighs 1.05 carats and measures 5.8 x 4.1 mm. While the macro photo here shows inclusions, the gem is eye clean, with just a few tiny crystal inclusions only visible with a loupe.