mineral

Amethyst

Crystalline Quartz (SiO2 with iron impurities)

Hardness: 7 on Mohs scale; Color: light to deep purple; Luster: vitreous (glassy); Crystal structure: Hexagonal (trigonal); Cleavage: none (conchoidal fracture); Specific gravity: 2.65

Hardness: 7 on Mohs scale
Color: light to deep purple
Luster: vitreous (glassy)

Identified March 25, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: light 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 inside igneous geodes when silica-rich fluids cool. The purple hue is caused by irradiation of trivalent iron (Fe3+) impurities. Formation can occur across various geological ages.

Uses & applications

Primarily used as a gemstone for jewelry, in ornamental carvings, and as a popular specimen for mineral collectors and metaphysical practitioners.

Geological facts

Amethyst was considered a 'Cardinal Gem' until large deposits were found in Brazil in the 1700s. Its name comes from the Greek 'amethystos', meaning 'not intoxicated', due to an ancient belief it prevented drunkenness.

Field identification & locations

Identify by its purple color, 6-sided crystal habit, and hardness (scratches glass but not a steel file). Commonly found in Brazil, Uruguay, Africa, and various parts of the USA (Arizona, Carolinas).

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