mineral

Amethyst (purple quartz)

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

AI-generated identification · may be incorrect

Hardness 7 Mohs; translucent lavender-purple color, vitreous luster, conchoidal fracture, trigonal crystal structure, and no cleavage. The piece appears cut or broken, with visible crystalline translucency.

Identified August 16, 2026More mineral →

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Physical properties

Formation & geological history

Forms in silica-rich hydrothermal fluids filling cavities in volcanic rocks, especially basaltic geodes; many amethysts formed during the Mesozoic and Cenozoic. The image alone cannot establish its precise age or locality.

Uses & applications

Used as a gemstone, ornamental stone, and collector specimen; lower-grade material is used for carvings, beads, and polished objects. It has no major structural or industrial use compared with ordinary quartz.

Geological facts

Purple color ranges from pale lilac to deep violet and can fade with prolonged heat or sunlight. Amethyst is February’s birthstone and a variety of quartz, not a separate mineral species.

Field identification & locations

Identify it by its purple color, glassy luster, hardness, and lack of cleavage; glass may imitate it but is generally softer and often contains bubbles. Common sources include Brazil, Uruguay, Zambia, and Bolivia.