mineral

Amethyst

Amethyst (Silicon Dioxide - SiO2 with impurities of iron)

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 5, 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

Formed in hydrothermal veins or cavities (geodes) within volcanic rock like basalt. The purple color comes from irradiation of iron impurities within the quartz crystal lattice. Specimens from places like Uruguay can be millions of years old.

Uses & applications

Primarily used in jewelry, as a decorative collector's item, and in alternative healing practices (metaphysical uses). Historically used for amulets and cups.

Geological facts

The name comes from the Ancient Greek 'amethystos', meaning 'not intoxicated', as it was believed to prevent drunkenness. It was once considered one of the 'cardinal gems' along with diamond and ruby before large deposits were found in South America.

Field identification & locations

Identify in the field by its distinct purple color and 6-sided hexagonal prisms. Often found in geode 'pockets' inside volcanic matrix. Common locations include Brazil, Uruguay, Zambia, and South Korea.

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