mineral

Amethyst

Quartz, SiO₂; purple variety colored mainly by iron impurities and irradiation

AI-generated identification · may be incorrect

Mohs hardness 7; translucent purple to violet, commonly with white quartz zones; vitreous luster, hexagonal crystal structure, and poor cleavage with conchoidal fracture. Specific gravity is about 2.65.

Identified August 23, 2026More mineral →

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Physical properties

Formation & geological history

Forms when silica-rich hydrothermal fluids fill cavities in volcanic rocks, especially basaltic lava flows; coloration develops from iron-bearing defects. Most specimens formed during relatively young volcanic episodes, commonly Mesozoic to Cenozoic.

Uses & applications

Used as a jewelry gemstone, ornamental stone, crystal specimens, and lapidary material. It is also popular in collections and metaphysical markets.

Geological facts

Amethyst is the birthstone for February and was historically valued alongside ruby, sapphire, and emerald. Heating can turn it yellow-orange, producing citrine.

Field identification & locations

Identify it by purple color, glassy luster, hardness sufficient to scratch ordinary glass, and quartz-like fracture; absence of obvious cubic cleavage helps distinguish it from fluorite. Major sources include Brazil, Uruguay, Zambia, and Morocco.