mineral

Black tourmaline pendant

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

AI-generated identification · may be incorrect

Opaque black, vitreous to resinous luster, commonly prismatic with longitudinal striations and trigonal crystal symmetry; Mohs hardness 7–7.5, no prominent cleavage, specific gravity about 3.1–3.3. The specimen appears polished and shaped as a faceted pendant, likely schorl.

Identified August 31, 2026More mineral →

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Physical properties

Formation & geological history

Forms in boron-rich granitic pegmatites and hydrothermal veins through late-stage igneous crystallization, generally in Phanerozoic rocks. Common sources include Brazil, Afghanistan, Madagascar, Pakistan, and the United States.

Uses & applications

Used as an ornamental gemstone, jewelry pendant, mineral specimen, and sometimes in metaphysical products; tourmaline’s piezoelectric and pyroelectric properties also have technical applications.

Geological facts

Tourmaline crystals can develop electrical charges when heated or compressed. Schorl is the most common tourmaline species and is iron-rich, accounting for its deep black color.

Field identification & locations

Identify by its black opaque color, elongated striated prisms, triangular or polygonal cross-section, and strong electrical response when heated or rubbed; distinguish from obsidian by crystal form and striations. The metal cap and chain are non-geological.