mineral

Black tourmaline bead bracelet, possibly mixed with smoky quartz or brown tourmaline

Schorl tourmaline, NaFe₃Al₆(BO₃)₃Si₆O₁₈(OH)₄; exact beads cannot be confirmed visually

AI-generated identification · may be incorrect

Opaque black to brown, vitreous to resinous luster, typically Mohs 7–7.5, trigonal crystal structure, and poor-to-indistinct cleavage. The polished spherical beads show reflective internal surfaces and occasional brown zoning.

Identified August 27, 2026More mineral →

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At a glance

Common name: Black tourmaline bead bracelet, possibly mixed with smoky quartz or brown tourmaline
Scientific name: Schorl tourmaline, NaFe₃Al₆(BO₃)₃Si₆O₁₈(OH)₄; exact beads cannot be confirmed visually
Category: mineral
Identified: August 27, 2026
Method: Standard

AI Estimated Value

Approximately $10–$40 for a common bracelet; $50–$150+ if made from well-identified, high-quality natural tourmaline.

Not an official valuation

AI estimate for general interest only — not an appraisal. Actual value depends on condition, provenance, and market demand. Verify with a professional before buying, selling, or insuring.

This identification was generated by AI and may contain errors. Verify important details before relying on them — and never use an AI result to judge whether a specimen is safe to handle. Read the full disclaimer

Physical properties

Formation & geological history

Tourmaline forms mainly in granitic pegmatites and metamorphic rocks, crystallizing from boron-rich fluids during late-stage igneous activity; specimens range from Precambrian to recent geological settings. Brown beads could instead be smoky quartz (SiO₂), Mohs 7.

Uses & applications

Used as ornamental beads, jewelry, and collector material; tourmaline is also valued for its piezoelectric and pyroelectric properties. Common polished bracelets generally have modest commercial value.

Geological facts

Schorl is the most common tourmaline species and often appears nearly opaque black. Rubbing or heating tourmaline can produce electrical charge, attracting light fibers or dust.

Field identification & locations

Common sources include Brazil, Afghanistan, Pakistan, Madagascar, Namibia, and the United States. Identify tourmaline by its strong polish, hardness, and—on rough material—striated prismatic crystals; a gemological test is needed to distinguish it from black onyx, obsidian, or glass.