Even rarer than alexandrite and cat’s eye is demantoid the green garnet. This beautiful green gem was discovered in the Urals of Russia in 1886, and has not been mined until recently . It derives its name from its diamond-like luster. Unlike most garnets, this gem looks like a green diamond. One interesting factor in demantoid garnets is that almost every Russian demantoid has a “horsetail” inclusion. This is one exception where an inclusion is actually a positive attribute. The stones tend to come bright green, with a yellow or blue secondary color. Most collectors do not purchase African demantoids.