mineral

Likely tumbled amethyst

Quartz, SiO₂; purple coloration from irradiation and trace iron

AI-generated identification · may be incorrect

Small rounded specimen with purple-gray color, vitreous to slightly dull luster, and apparent internal fractures or banding. Quartz hardness is Mohs 7, lacks cleavage, has hexagonal crystal structure, and specific gravity about 2.65.

Identified August 24, 2026More mineral →

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Physical properties

Formation & geological history

Amethyst forms when iron-bearing quartz crystallizes in volcanic cavities, commonly in basaltic geodes; coloration develops through irradiation and heating over geological time. The photographed piece appears polished or naturally water-worn, so original crystal faces are absent.

Uses & applications

Used as an ornamental gemstone, carvings, jewelry, lapidary material, and mineral-collection specimen. Small common tumbled pieces have modest commercial value.

Geological facts

The identification is visual and not certain because the specimen is very small and partially obscured; purple fluorite, dyed quartz, or another violet mineral are possible alternatives.

Field identification & locations

Look for quartz-like glassy luster, hardness sufficient to scratch ordinary glass, no obvious cleavage, and purple zoning or inclusions. Common sources include Brazil, Uruguay, Zambia, and Mexico.