Demantoid is the green gemstone variety of the mineral andradite, a member of the garnet group of minerals chromium is the cause of the demantoid green color. While garnets have been known since. Ancient times, the Demantoid variety was not discovered until 1853. Today many countrys have been found to have depsoits including Russia and Namibia, Demantoids are also found in other locations including Italy (Val Malenco, Lombardy), Iran (Kerman) and Afghanistan
In around 2009, there was a significant discovery of Demantoid and andradite garnet in Madagascar.
Mohs scale hardness 6.5-7.0
Refractive index 1.880 - 1.889