mineral

Amethyst

SiO2 (Silicon Dioxide with iron impurities)

Hardness: 7 (Mohs scale); Color: Purple to violet due to irradiation and iron impurities; Luster: Vitreous (glassy); Crystal Structure: Hexagonal/Trigonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 (Mohs scale)
Color: Purple to violet due to irradiation and iron impurities
Luster: Vitreous (glassy)

Identified May 3, 2026More mineral →

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Physical properties

Formation & geological history

Formed in cavities (geodes) of volcanic rocks (basalt) or hydrothermal veins via the precipitation of silica from mineral-rich fluids. Can be found in rocks from various geological eras, including the Cretaceous.

Uses & applications

Highly valued as a gemstone for jewelry (rings, necklaces), used in decorative items and carvings, and frequently collected as mineral specimens by enthusiasts.

Geological facts

The name comes from the Greek word 'amethystos', meaning 'not intoxicated', as it was once believed to prevent drunkenness. It is the official birthstone for February.

Field identification & locations

Identify in the field by its distinct purple color and crystal habit. Common locations include Brazil, Uruguay, Madagascar, and Arizona, USA. Beginners should look for its hexagonal prism shape and glassy luster.