mineral

Tourmaline

Schorl (Complex boron silicate, NaFe3Al6(Si6O18)(BO3)3(OH)4)

AI-generated identification · may be incorrect

Hardness: 7 to 7.5 on the Mohs scale. Color: Typically black (schorl). Luster: Vitreous to resinous. Crystal structure: Trigonal, prismatic crystals often with striated faces. Cleavage: Indistinct. Specific gravity: 3.0 to 3.2

Hardness: 7 to 7
Color: Typically black (schorl)
Luster: Vitreous to resinous

Identified July 30, 2026More mineral →

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Physical properties

Formation & geological history

Forms in pegmatites, hydrothermal veins, and metamorphic rocks like schists and gneisses through the crystallization of boron-rich magmatic fluids.

Uses & applications

Used in gemstone and jewelry trade, industrial applications due to piezoelectric and pyroelectric properties, and as a popular mineral specimen for collectors.

Geological facts

Tourmaline has one of the widest color ranges of any mineral group, but black tourmaline (schorl) accounts for about 95% of all tourmaline found in nature.

Field identification & locations

Easily identified by its characteristic prismatic crystal habit with distinct vertical striations and triangular cross-sections. Found worldwide, with notable deposits in Brazil, Africa, the United States, and Madagascar.