mineral

Amethyst crystal

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

AI-generated identification · may be incorrect

Typically Mohs hardness 7, vitreous luster, translucent purple color, hexagonal crystal structure, and no cleavage; conchoidal fracture. The specimen appears to be a natural, somewhat worn or partially polished crystal cluster.

Identified August 15, 2026More mineral →

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Physical properties

Formation & geological history

Forms when silica-rich hydrothermal fluids fill cavities in volcanic rocks, especially basaltic lava flows; purple quartz commonly crystallizes during late-stage cavity growth, generally from the Mesozoic to Cenozoic in major deposits.

Uses & applications

Used as a gemstone, ornamental specimen, and metaphysical collectible; durable examples are cut into faceted gems or cabochons. Common quality pieces have modest commercial value.

Geological facts

Amethyst’s purple color can fade with prolonged heating or intense sunlight. Its color ranges from pale lilac to deep violet, with darker zoning often indicating higher desirability.

Field identification & locations

Identify it by purple color, glassy luster, hardness sufficient to scratch ordinary glass, and quartz-like conchoidal fracture; distinguish it from fluorite, which is softer and cleaves easily. Major sources include Brazil, Uruguay, Zambia, and Bolivia.