mineral

Amethyst crystal cluster

Amethyst, purple quartz (SiO₂) colored mainly by iron impurities and irradiation

AI-generated identification · may be incorrect

Mohs hardness 7; vitreous luster; transparent to translucent purple crystals with hexagonal/trigonal quartz structure and no cleavage, showing conchoidal fracture. Specific gravity is about 2.65.

Identified August 10, 2026More mineral →

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Physical properties

Mohs hardness 7; vitreous luster; transparent to translucent purple crystals with hexagonal/trigonal quartz structure and no cleavage, showing conchoidal fracture. Specific gravity is about 2.65.

Formation & geological history

Forms when silica-rich hydrothermal fluids or volcanic gases deposit quartz in cavities and vugs, commonly in basaltic lava flows; many commercial specimens formed during the Mesozoic to Cenozoic. Purple color develops from iron-related defects exposed to natural radiation.

Uses & applications

Used for faceted gemstones, cabochons, beads, carvings, mineral specimens, and decorative objects. It is also popular in metaphysical collections, though claimed healing properties are unproven.

Geological facts

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

Field identification & locations

Identify by its purple color, glassy luster, hardness, hexagonal crystal points, and lack of cleavage; it commonly occurs with white or gray quartz and basalt matrix. Major sources include Brazil, Uruguay, Zambia, Bolivia, and Namibia.