a rare member of the tourmaline group:Calcium Iron Magnesium Aluminum Boro-silicate Hydroxide; the general formula is :Ca(Mg, Fe)3Al5MgSi6O18(BO3)3(OH)3 and hardness of 7.5.
Is a an interesting type of tourmaline that crystalized in short stubby shapes instead of the normal elongated prismatic crystals. The colors range from green to brownish black, rarely also colorless. Quite rare to find clean stones,most of the crystal tend to be full of flaws and often translucent.
Weight: 1.20 ct.