gemstone

Polished brown gemstone, likely smoky quartz

Smoky quartz (quartz, SiO₂), possibly brown chalcedony or tiger’s-eye based on the photograph

AI-generated identification · may be incorrect

Translucent brown to honey color with a vitreous polish and no visible crystals; quartz has Mohs hardness 7, conchoidal fracture, hexagonal crystal structure, and specific gravity about 2.65. The rounded shape indicates a tumbled or cabochon-cut specimen.

Identified September 18, 2026More gemstone →

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At a glance

Common name: Polished brown gemstone, likely smoky quartz
Scientific name: Smoky quartz (quartz, SiO₂), possibly brown chalcedony or tiger’s-eye based on the photograph
Category: gemstone
Identified: September 18, 2026
Method: Standard

AI Estimated Value

About $2–$15 for a small common tumbled stone; $20–$75 if it is unusually transparent, well-shaped, or confirmed as a quality gemstone.

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

Smoky quartz forms when natural radiation colors quartz in granitic pegmatites, hydrothermal veins, and metamorphic rocks, generally from Precambrian to younger geologic settings. Exact identification and age require testing or provenance.

Uses & applications

Used for inexpensive jewelry, lapidary ornaments, carvings, and mineral collecting. Common polished pieces typically have modest commercial value.

Geological facts

Color intensity comes from radiation-induced defects associated with aluminum impurities; heating can remove the smoky color. Similar brown stones include glass, jasper, amber, and tiger’s-eye.

Field identification & locations

Check for quartz-like hardness, glassy luster, and conchoidal fracture; a steel file should not scratch it, while quartz should scratch ordinary glass. Common sources include Brazil, Madagascar, Switzerland, and the United States.