Tourmaline
Tourmaline
(Na,Ca)(Mg,Li,Al,Fe2+)3Al6(BO3)3Si6O18(OH)4
Complex Borosilicate
Hardness: 7-7.5
Cyclosilicate
Trigonal System
Most commonly black, but can range from colorless, brown, violet, yellow, orange, blue, red, green, pink
Tourmaline
(Na,Ca)(Mg,Li,Al,Fe2+)3Al6(BO3)3Si6O18(OH)4
Complex Borosilicate
Hardness: 7-7.5
Cyclosilicate
Trigonal System
Most commonly black, but can range from colorless, brown, violet, yellow, orange, blue, red, green, pink
