mineral

Amethyst

Silicon Dioxide with iron impurities (SiO2)

Hardness: 7 on Mohs scale; Color: Purple to violet; Luster: Vitreous (glass-like); Crystal structure: Hexagonal/Trigonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Hardness: 7 on Mohs scale
Color: Purple to violet
Luster: Vitreous (glass-like)

Identified March 27, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Purple to violet; Luster: Vitreous (glass-like); Crystal structure: Hexagonal/Trigonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Formation & geological history

Formed in hydrothermal veins or cavities (geodes) within igneous rocks. The purple color is caused by natural irradiation of trace iron impurities within the quartz crystal lattice.

Uses & applications

Primarily used in jewelry, as decorative gemstones, and in crystal collecting. Historically used for amulets and vessels.

Geological facts

Amethyst is the birthstone for February and was once considered as valuable as diamonds or rubies until large deposits were found in Brazil. The name comes from the Greek 'amethystos', meaning 'not intoxicated'.

Field identification & locations

Identify by its purple hue and hexagonal crystal faces. Found worldwide with major deposits in Brazil and Uruguay. Collectors should look for deep, uniform color and clarity.

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