BLT193 Black Tourmaline Intarsia Beads 5 on the Mohs hardness

5 on the Mohs hardness scale

Material that is visibly quartz or overly fractured has been graded out

5 to 7 on the Mohs Scale

Additionally the rock can contain tube formations

BLT193 Black Tourmaline Intarsia Beads 5 on the Mohs hardnessBlack Tourmaline crystal with termination. 3. 5" x 3" x 2. 5" 1. 55 lb Black Tourmaline is also called Schorl, and accounts for ninety five percent of all Tourmaline in nature. It is black, or sometimes a deep blue that appears black. The term Schorl was in use before the 1400s, named for a town in Saxony, Germany, where Black Tourmaline was found in nearby tin mines. Black Tourmaline belongs to a complex family of aluminum borosilicate mixed with