mineral

Amethyst

Amethyst (variety of Quartz, SiO2)

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

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

Identified April 4, 2026More mineral →

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Physical properties

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

Formation & geological history

Forms in hydrothermal veins and basaltic geodes. It is colored by irradiation of trace amounts of iron (Fe3+) in the crystal structure. It can be found in rocks ranging from several million to billions of years old.

Uses & applications

Primary use is in jewelry, gemstone collecting, and interior decoration as geodes. Historically used as an amulet against drunkenness.

Geological facts

Amethyst was considered a 'Cardinal Gem' until the 18th century, ranked alongside diamonds and rubies in value until major deposits were discovered in Brazil. Its name comes from the Greek 'amethystos', meaning 'not intoxicated'.

Field identification & locations

Identify in the field by its purple color and hardness (it will scratch glass and steel). Common locations include Brazil, Uruguay, Zambia, and Ontario, Canada. Collectors should look for deep, uniform color and transparency.