mineral

Amethyst

SiO2 (Silicon Dioxide with iron impurities)

Hardness: 7 (Mohs scale); Color: Purple, violet, Lavender; Luster: Vitreous/glassy; Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Hardness: 7 (Mohs scale)
Color: Purple, violet, Lavender
Luster: Vitreous/glassy

Identified May 21, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale); Color: Purple, violet, Lavender; Luster: Vitreous/glassy; Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Formation & geological history

Forms in hydrothermal veins or as linings in geodes (amygdules) within volcanic rocks. The purple color is caused by irradiation of trivalent iron impurities within the quartz crystal structure.

Uses & applications

Primarily used in jewelry (faceting, cabochons), ornamental decoration, and as a popular specimen for mineral collectors.

Geological facts

Amethyst was considered a precious stone in ancient times, comparable to Diamond and Ruby, until large deposits were found in Brazil. Its name comes from the Greek word 'amethystos', meaning 'not intoxicated'.

Field identification & locations

Identify by its characteristic purple hue, hexagonal crystal points, and inability to be scratched by a steel knife. Commonly found in Brazil, Uruguay, Zambia, and Canada.