Black Tourmaline - Scientific Description

Black Tourmaline - Scientific Description

Black Tourmaline   Scientific Name: Schrol Chemical Formula: NaFe2+3Al6(BO3)3Si6O18(OH)4 Composition: Basic sodium iron aluminum boro-silicate Color: Black Mohs Hardness: 7 – 7.5 Crystal System: Hexagonal Rock Type: Igneous, Metamorphic Lustre:...