mineral

Black tourmaline (schorl) in a light-colored host rock

Schorl, NaFe₃Al₆(BO₃)₃Si₆O₁₈(OH)₄

AI-generated identification · may be incorrect

The dark crystals appear black and opaque with a vitreous-to-submetallic luster; tourmaline is Mohs 7–7.5, trigonal, and has no cleavage with uneven fracture. The pale host appears quartz- or feldspar-rich, but the photo alone does not confirm its identity.

Identified October 14, 2026More mineral →

Explore Black tourmaline (schorl) in a light-colored host rock in the encyclopedia →

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Physical properties

Formation & geological history

Schorl commonly crystallizes in boron-rich granitic pegmatites and hydrothermal veins; the host may be pegmatitic or another light-colored rock. Its age depends on the deposit, often ranging from Precambrian to recent geological periods.

Uses & applications

Tourmaline is used as a durable jewelry and collector mineral; black schorl is also valued in mineral specimens. Quartz- and feldspar-rich host rocks have common industrial uses.

Geological facts

Tourmaline crystals can develop strong electrical charges when heated or compressed (pyroelectric and piezoelectric effects).

Field identification & locations

Look for black, elongated or striated crystals and their hardness, though the pictured material appears broken and identification is provisional. Tourmaline-bearing pegmatites occur worldwide, including Brazil, Afghanistan, and the United States.