mineral

Amethyst

Silicon Dioxide (SiO2) with iron impurities

Hardness: 7 on Mohs scale; Color: Purple, violet, to deep reddish-purple; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: Purple, violet, to deep reddish-purple
Luster: Vitreous (glassy)

Identified March 23, 2026More mineral →

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Physical properties

Formation & geological history

Formed in igneous and metamorphic environments, most commonly inside hydrothermal veins or volcanic geodes. The purple color is caused by natural irradiation of trace iron impurities within the quartz lattice. Geological age varies by deposit, ranging from 100 million to over 1 billion years old.

Uses & applications

Primary use is in jewelry (faceted gemstones, cabochons) and as decorative specimens for collectors. It is also historically used in 'alternative healing' sets and as the birthstone for February.

Geological facts

The name comes from the Ancient Greek 'amethystos', meaning 'not intoxicated', as it was believed to protect its owner from drunkenness. Until the 18th century, amethyst was included in the cardinal gemstones alongside diamond, sapphire, ruby, and emerald.

Field identification & locations

Identify in the field by its hexagonal crystal habit, purple hue, and inability to be scratched by a steel knife. Common locations include Brazil (Rio Grande do Sul), Uruguay, Zambia, and Russia. Collectors should look for deep 'Siberian' purple saturation with red flashes and high clarity.

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