mineral

Amethyst

Quartz (SiO2) with iron impurities

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

Hardness: 7 on Mohs scale
Color: Pale violet to deep purple
Luster: Vitreous

Identified July 14, 2026More mineral →

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Physical properties

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

Formation & geological history

Formed in hydrothermal veins and cavities (geodes) within igneous and metamorphic rocks. The purple color results from irradiation of trivalent iron impurities (Fe3+) in the quartz structure. Typical formation ages range from millions to hundreds of millions of years.

Uses & applications

Primarily used as a gemstone in jewelry, for decorative carvings, and as a popular collector specimen. Historically used as a protective amulet against intoxication.

Geological facts

The name comes from the Greek word 'amethystos', meaning 'not intoxicated'. Until the 18th century, it was considered one of the 'cardinal' gemstones, valued as highly as diamonds and rubies until large deposits were found in Brazil.

Field identification & locations

Identify by its purple hue, quartz-like fracture, and hexagonal crystal habit. It is commonly found in Brazil, Uruguay, Madagascar, and the United States (Arizona/North Carolina). Collectors look for deep saturation and clarity.