mineral

Tumbled amethyst

Amethyst, purple variety of quartz (SiO₂)

AI-generated identification · may be incorrect

Mohs hardness 7; translucent purple with vitreous luster and irregular conchoidal fracture. Trigonal crystal system; no cleavage. The specimen is polished, so natural crystal faces are absent.

Identified September 25, 2026More mineral →

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Physical properties

Mohs hardness 7; translucent purple with vitreous luster and irregular conchoidal fracture. Trigonal crystal system; no cleavage. The specimen is polished, so natural crystal faces are absent.

Formation & geological history

Forms when iron-bearing quartz crystallizes in silica-rich fluids, commonly lining volcanic-rock cavities; color develops through irradiation and trace iron. Amethyst deposits range from ancient to geologically recent.

Uses & applications

Used for jewelry, ornaments, and mineral collecting; quartz is also important in glassmaking and electronics.

Geological facts

Amethyst’s purple color varies with iron content and natural or artificial heating can turn it yellow, producing citrine-like material.

Field identification & locations

Identify by its purple color, glassy luster, and hardness sufficient to scratch glass; common sources include Brazil, Uruguay, Zambia, and Russia. This appears to be a small tumbled piece.