mineral

Black tourmaline pendant

Schorl, a sodium–iron tourmaline; approximate formula NaFe₃Al₆(BO₃)₃Si₆O₁₈(OH)₄

AI-generated identification · may be incorrect

The polished, elongated black stone is consistent with schorl, though the photo cannot confirm its identity. Tourmaline has Mohs hardness 7–7.5, vitreous luster, a trigonal crystal structure, and poor cleavage; specific gravity is about 3.0–3.3.

Identified October 11, 2026More mineral →

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Physical properties

Formation & geological history

Tourmaline commonly crystallizes in granitic pegmatites and metamorphic rocks as boron-rich fluids cool. It occurs in rocks ranging from Precambrian to recent geological settings.

Uses & applications

Black tourmaline is used in jewelry and mineral collections; tourmaline varieties also have applications in instruments and electronics due to their electrical properties.

Geological facts

Schorl is the most common tourmaline species. Its long, striated crystals are often polished into pendants like this one.

Field identification & locations

A likely identification is based on the glossy black color and elongated form, but other black minerals could look similar. Schorl is found worldwide, including Brazil, Afghanistan, and the United States; hardness and crystal striations can help distinguish it.