mineral

Amethyst crystal fragment

Quartz, SiO₂; purple variety colored mainly by irradiation-related iron impurities

AI-generated identification · may be incorrect

Pale violet, translucent, vitreous luster, and likely hexagonal quartz structure; hardness Mohs 7, no cleavage, conchoidal fracture, specific gravity about 2.65. The specimen appears naturally terminated or roughly broken, with visible crystal faces and inclusions.

Identified September 13, 2026More mineral →

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Physical properties

Formation & geological history

Forms when silica-rich hydrothermal fluids or groundwater fill cavities in volcanic rocks, especially basaltic geodes; purple quartz commonly crystallized during the Cenozoic to older volcanic episodes, depending on locality.

Uses & applications

Used as a gemstone, ornamental crystal, lapidary material, and mineral-collection specimen; small fragments have modest commercial value.

Geological facts

Amethyst’s purple color can fade with prolonged heating or strong sunlight, and heating may produce yellow citrine-like quartz.

Field identification & locations

Identify by purple color, glassy luster, hardness sufficient to scratch ordinary glass, and lack of cleavage; common sources include Brazil, Uruguay, Zambia, Namibia, and Mexico. This tiny piece may be a broken geode crystal rather than a complete point.