mineral

Amethyst-bearing quartz (rough/tumbled fragment)

Quartz, SiO₂; purple coloration from irradiation and trace iron

AI-generated identification · may be incorrect

Mohs hardness 7; purple to lilac, translucent, with vitreous-to-waxy luster and no cleavage, showing conchoidal fracture. The rounded, abraded form suggests a tumbled or naturally water-worn piece; visible whitish zones may be milky quartz or druzy quartz.

Identified August 10, 2026More mineral →

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Physical properties

Formation & geological history

Forms mainly in gas cavities and fractures of volcanic rocks, especially basalt, when silica-rich hydrothermal fluids deposit quartz. Most commercial amethyst formed during the Cenozoic to Mesozoic eras, though ages vary by locality.

Uses & applications

Used as a gemstone, ornamental stone, crystal specimen, and in carvings; lower-grade material is sold for décor and metaphysical collecting.

Geological facts

Amethyst is the purple variety of quartz and can fade with prolonged heat or intense sunlight. Its purple color commonly occurs in zoning, with pale or colorless quartz transitions.

Field identification & locations

Common sources include Brazil, Uruguay, Zambia, Namibia, and Mexico. Identify it by purple quartz hardness, glassy luster, lack of cleavage, and resistance to scratching by a steel knife; exact locality cannot be confirmed from the image.