gemstone

Tumbled amethyst (likely)

Quartz, SiO₂; purple coloration from trace iron and irradiation

AI-generated identification · may be incorrect

Mohs hardness 7; translucent purple-to-lavender body with white quartz zones, vitreous luster, and no visible cleavage. The rounded, polished shape indicates a tumbled specimen; specific gravity is about 2.65.

Identified September 17, 2026More gemstone →

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Physical properties

Formation & geological history

Forms when iron-bearing quartz crystallizes in gas cavities of volcanic rocks, especially basalt, and later develops purple color through natural irradiation. Many commercial pieces formed in Mesozoic–Cenozoic volcanic regions, though exact age is locality-dependent.

Uses & applications

Used as an ornamental stone, jewelry material, meditation/collecting specimen, and decorative aggregate. This small polished piece has modest commercial value.

Geological facts

Amethyst is the purple variety of quartz and is the traditional February birthstone. Its color can fade with prolonged strong heat or sunlight.

Field identification & locations

Identify it by purple quartz, glassy luster, hardness sufficient to scratch ordinary glass, and lack of cleavage; confirm with a gemological test because dyed glass or fluorite can resemble it. Major sources include Brazil, Uruguay, Zambia, and Bolivia.