mineral

Amethyst

Quartz, crystalline silica (SiO₂), purple variety

AI-generated identification · may be incorrect

Typically translucent purple with a vitreous luster and hexagonal crystal structure; Mohs hardness 7, no cleavage, uneven to conchoidal fracture, and specific gravity about 2.65. The specimen appears to be a rough, fractured amethyst fragment, possibly with pale quartz zoning.

Identified August 16, 2026More mineral →

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Physical properties

Formation & geological history

Forms mainly in cavities and fractures of volcanic rocks when silica-rich hydrothermal fluids deposit quartz; purple color results chiefly from iron impurities and irradiation. Most commercial material formed in younger volcanic environments, especially Brazil and Uruguay, though exact age depends on locality.

Uses & applications

Used for jewelry, carvings, geodes, metaphysical objects, and mineral collecting; large crystal clusters and vivid, transparent material are most desirable.

Geological facts

Amethyst is the purple member of the quartz family and is February’s birthstone. Heating can turn it yellow-orange, producing citrine-like material.

Field identification & locations

Identify it by its purple color, glassy luster, hardness, and lack of cleavage; quartz will scratch glass but not be scratched by a steel knife. Common sources include Brazil, Uruguay, Zambia, and Namibia.