mineral

Polished tourmalinated quartz

Quartz (SiO₂) with black schorl tourmaline (NaFe₃Al₆(BO₃)₃Si₆O₁₈(OH)₄) inclusions

AI-generated identification · may be incorrect

Typically hardness 7 for quartz and 7–7.5 for schorl; translucent gray-clear quartz contains irregular black, vitreous tourmaline patches or needles. Quartz is trigonal with no cleavage; tourmaline is trigonal and has indistinct cleavage. Specific gravity is about 2.65–3.2.

Identified August 9, 2026More mineral →

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At a glance

Common name: Polished tourmalinated quartz
Scientific name: Quartz (SiO₂) with black schorl tourmaline (NaFe₃Al₆(BO₃)₃Si₆O₁₈(OH)₄) inclusions
Category: mineral
Identified: August 9, 2026
Method: Standard

AI Estimated Value

About $5–$25 for a small polished common piece; $30–$100+ for larger, sharply patterned, translucent, or locality-labeled specimens.

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

Forms in hydrothermal quartz veins and pegmatites, where tourmaline crystallizes within growing quartz. Specimens may range from Paleozoic to Mesozoic or younger depending on locality.

Uses & applications

Used for cabochons, polished palm stones, beads, and ornamental objects; attractive examples are popular with mineral collectors.

Geological facts

The black component is usually schorl, the most common iron-rich tourmaline. The specimen appears intentionally cut and polished into a rounded cabochon or worry stone.

Field identification & locations

Identify it by its glassy quartz matrix and contrasting black tourmaline inclusions; unlike black mica, tourmaline does not split into flexible sheets. Common sources include Brazil, Madagascar, Pakistan, and the United States.