mineral

Raw amethyst quartz

Amethyst, purple variety of quartz (SiO₂)

AI-generated identification · may be incorrect

Hardness 7 Mohs; translucent purple to lavender, with a vitreous luster and conchoidal fracture. Trigonal quartz crystals are present or partly obscured; the pale matrix may include milky quartz and minor host-rock material.

Identified September 13, 2026More mineral →

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Physical properties

Formation & geological history

Forms when iron-bearing quartz is irradiated by natural radiation in volcanic cavities, hydrothermal veins, and geodes. Individual specimens commonly formed during relatively young volcanic episodes, though exact age depends on locality.

Uses & applications

Used for jewelry, carvings, polished specimens, and mineral collecting; gem-quality material has greater value than cloudy or fractured pieces.

Geological facts

Purple color results mainly from irradiation-induced defects involving iron impurities. Heating can produce yellow citrine or reddish-brown “burnt amethyst.”

Field identification & locations

Identify by purple zoning, glassy luster, hardness sufficient to scratch glass, and lack of obvious cleavage; quartz fractures rather than cleaves. Common sources include Brazil, Uruguay, Zambia, Bolivia, and Mexico.