mineral

Black Tourmaline

Schorl (NaFe3Al6(BO3)3Si6O18(OH)4)

AI-generated identification · may be incorrect

Hardness: 7-7.5 (Mohs scale), Color: Inky black, Luster: Vitreous to sub-metallic, Crystal Structure: Trigonal/Hexagonal columns with vertical striations, Cleavage: Indistinct/Poor, Specific Gravity: 3.0-3.2

Hardness: 7-7

Identified July 6, 2026More mineral →

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Physical properties

Formation & geological history

Commonly formed in granitic pegmatites, hydrothermal veins, and metamorphic rocks such as schists. It is a complex borosilicate mineral formed through igneous and metamorphic processes over millions of years.

Uses & applications

Used primarily in jewelry as a gemstone, as a source of boron in industry, and widely collected as a metaphysical healing crystal or decorative mineral specimen. Historically used for scientific experiments due to its pyroelectric properties.

Geological facts

Black Tourmaline is pyroelectric and piezoelectric, meaning it generates an electrical charge when heated or subjected to pressure. Victorian grieving jewelry often used black tourmaline as a substitute for jet.

Field identification & locations

Identify in the field by its characteristic long, needle-like or columnar crystals with vertical grooves (striations) and a triangular cross-section. Commonly found in Brazil, Africa, and the USA (California and Maine).