mineral

Black Tourmaline

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

AI-generated identification · may be incorrect

Hardness of 7 to 7.5 on the Mohs scale, deep black color, vitreous to submetallic luster, trigonal crystal system with striated prismatic crystals, conchoidal fracture with no true cleavage, and specific gravity of 3.20 to 3.26.

Identified August 7, 2026More mineral →

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Physical properties

Formation & geological history

Forms in igneous and metamorphic environments, particularly in pegmatites, granites, and hydrothermal veins where boron-rich fluids interact with surrounding rocks.

Uses & applications

Widely used in jewelry, ornamental carvings, metaphysical crystal collections, and industrial applications due to its pyroelectric and piezoelectric properties.

Geological facts

Black tourmaline, or schorl, is the most common variety of tourmaline, accounting for about 95% of all tourmaline found in nature. It was historically referred to by miners as schorl before the name was standardized.

Field identification & locations

Easily identifiable in raw form by its distinct triangular cross-section and deeply striated vertical column faces. Found globally, with notable deposits in Brazil, Africa, Pakistan, and the United States.