mineral

Tumbled amethyst

Quartz (SiO₂), purple variety colored by trace iron and irradiation

AI-generated identification · may be incorrect

Mohs hardness 7; purple to violet with a vitreous luster and no cleavage, breaking with conchoidal fracture. The visible specimen is polished and elongated; its crystal structure is trigonal.

Identified October 5, 2026More mineral →

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Physical properties

Mohs hardness 7; purple to violet with a vitreous luster and no cleavage, breaking with conchoidal fracture. The visible specimen is polished and elongated; its crystal structure is trigonal.

Formation & geological history

Amethyst typically crystallizes from silica-rich fluids in cavities of volcanic rocks, often over millions of years; the image does not reveal its precise age or source.

Uses & applications

Used in jewelry, ornaments, and mineral collections; lower-grade material is commonly tumbled for decorative use.

Geological facts

Amethyst’s color is associated with trace iron and natural radiation within quartz. It can fade with prolonged exposure to strong sunlight.

Field identification & locations

Identify by its purple color, glassy luster, hardness, and lack of cleavage; common sources include Brazil, Uruguay, and Zambia. This small tumbled piece is likely worth about $1–$10 USD.