mineral

Black Tourmaline (Schorl)

Schorl (NaFe2+3Al6(BO3)3Si6O18(OH)4)

AI-generated identification · may be incorrect

Hardness: 7-7.5. Color: Inky black. Luster: Vitreous to sub-metallic. Crystal system: Trigonal/Hexagonal. Cleavage: Indistinct. Specific Gravity: 3.0-3.25. Typically forms elongated prismatic crystals with vertical striations.

Hardness: 7-7
Color: Inky black
Luster: Vitreous to sub-metallic

Identified July 2, 2026More mineral →

Explore Black Tourmaline (Schorl) in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Formation & geological history

Forms primarily in granitic pegmatites and metamorphic rocks like schists during hydrothermal processes. Most common species in the tourmaline group, appearing in high-temperature environments.

Uses & applications

Extensively used for protection jewelry, metaphysical practices, and mineral collection. Industrially, it has been used in pressure gauges due to its piezoelectric and pyroelectric properties.

Geological facts

Schorl is known for its ability to become electrically charged when heated (pyroelectricity) or rubbed (piezoelectricity). It is by far the most abundant member of the complex tourmaline mineral group.

Field identification & locations

Identify by its deep black color, vertical striations on crystal faces, and a rounded triangular cross-section. Commonly found in Brazil, Namibia, and the United States (Maine/California).