mineral

Black tourmaline bead bracelet

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

AI-generated identification · may be incorrect

Opaque black, typically vitreous to resinous luster; Mohs hardness 7–7.5, trigonal crystal structure, poor cleavage, specific gravity about 3.0–3.3. The rounded beads are polished and may show subtle striations or inclusions.

Identified August 13, 2026More mineral →

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Physical properties

Formation & geological history

Forms mainly in granite pegmatites and metamorphic rocks from boron-rich hydrothermal fluids; tourmaline occurs from Precambrian to recent geological settings. The beads are human-shaped and polished from natural material.

Uses & applications

Used for jewelry, carvings, mineral specimens, and collecting; it is also popular in decorative and metaphysical markets. It has limited industrial use as a durable boron-bearing mineral.

Geological facts

Schorl is the most common black tourmaline variety and commonly contains iron. Tourmaline is strongly piezoelectric and becomes electrically polarized when heated or compressed.

Field identification & locations

Identify by its deep black color, relatively high hardness, dense feel, and commonly striated prismatic crystals; confirm with gemological testing because black glass, onyx, and dyed stones can look similar. Common sources include Brazil, Afghanistan, Pakistan, Madagascar, Namibia, and the United States.