mineral

Amethyst (Quartz)

Amethyst (Silicon Dioxide with Iron impurities), SiO2

Hardness: 7 on Mohs scale; Color: Pale violet to deep purple; Luster: Vitreous (glassy); 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 (glassy)

Identified March 22, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Pale violet 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 and hollow cavities (geodes) within igneous rocks. The purple color is caused by irradiation of trivalent iron (Fe3+) impurities within the quartz crystal lattice. Found in rocks ranging from precambrian to recent volcanic deposits.

Uses & applications

Primarily used as a gemstone in jewelry, for ornamental carvings, and as a popular decorative display specimen for crystal collectors.

Geological facts

Amethyst was considered one of the five cardinal gemstones until large deposits were found in Brazil. The name comes from the Ancient Greek 'amethystos', meaning 'not intoxicated', as it was once believed to prevent drunkenness.

Field identification & locations

Identify by its characteristic purple color and hexagonal crystal points. It can be found globally, with major commercial deposits in Brazil and Uruguay. Collectors should look for deep uniform color and lack of inclusions.

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