mineral

Amethyst

Silicon Dioxide with trace inclusions of Iron (SiO2)

Hardness: 7 (Mohs scale); Color: Pale lilac to deep purple; Luster: Vitreous; Crystal system: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Hardness: 7 (Mohs scale)
Color: Pale lilac to deep purple
Luster: Vitreous

Identified March 18, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale); Color: Pale lilac to deep purple; Luster: Vitreous; Crystal system: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Formation & geological history

Formed in hydrothermal veins and hollow gas cavities (geodes) within volcanic rocks. The purple color is caused by natural irradiation of trace iron impurities within the quartz crystal lattice. Specimens can range from thousands to millions of years old.

Uses & applications

Extensively used in jewelry (faceting, beads, cabochons), as an ornamental stone in home decor, and widely sought by mineral collectors. It is the birthstone for February.

Geological facts

Until the 18th century, amethyst was included in the cardinal gemstones along with diamond, ruby, emerald, and sapphire. Ancient Greeks believed it could prevent intoxication; translated from 'amethystos', it literally means 'not drunk'.

Field identification & locations

Identify in the field by its distinct purple hue, hexagonal crystal shape, and inability to be scratched by a steel knife. Common locations include Brazil (Rio Grande do Sul), Uruguay, Zambia, and South Korea.

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