mineral

Tumbled amethyst

Quartz, purple variety; silicon dioxide (SiO₂), colored mainly by iron impurities and irradiation

AI-generated identification · may be incorrect

Mohs hardness 7; purple to violet, vitreous luster, translucent to opaque, trigonal crystal structure, and indistinct cleavage with conchoidal fracture. The rounded surface indicates tumbling and polishing.

Identified August 25, 2026More mineral →

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Physical properties

Formation & geological history

Amethyst forms when iron-bearing quartz crystallizes in gas cavities of volcanic rocks, especially basalt, with later irradiation producing the purple color. Most specimens formed in geologically young-to-ancient volcanic environments; the image alone cannot establish age.

Uses & applications

Used for jewelry, carvings, ornaments, meditation stones, and mineral collecting. Common tumbled pieces typically have modest commercial value.

Geological facts

Color can fade with prolonged heat or intense sunlight; heating may turn amethyst yellow or orange, producing citrine-like material. Amethyst is February’s birthstone.

Field identification & locations

Common sources include Brazil, Uruguay, Zambia, and Madagascar. Identify it by purple color, glassy luster, hardness sufficient to scratch ordinary glass, and quartz-like fracture; a definitive ID may require testing because dyed glass or other purple minerals can resemble it.