mineral

Tumbled amethyst

Amethyst, purple variety of quartz (SiO₂)

AI-generated identification · may be incorrect

Mohs hardness 7; purple, vitreous luster, trigonal crystal structure, and no cleavage. The pictured piece is polished and rounded; its exact identity cannot be confirmed from the image alone.

Identified October 12, 2026More mineral →

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Physical properties

Mohs hardness 7; purple, vitreous luster, trigonal crystal structure, and no cleavage. The pictured piece is polished and rounded; its exact identity cannot be confirmed from the image alone.

Formation & geological history

Amethyst crystallizes from silica-rich fluids in cavities and veins, commonly in volcanic rocks; deposits range from millions to hundreds of millions of years old.

Uses & applications

Used in jewelry, ornaments, and mineral collections; tumbling produces a smooth decorative finish.

Geological facts

Its purple color comes mainly from trace iron and natural irradiation. Amethyst is the purple variety of quartz.

Field identification & locations

Look for purple color, glassy luster, and hardness sufficient to scratch glass; common sources include Brazil, Uruguay, and Zambia. A small tumbled piece like this commonly sells for about $2–$15 USD.