mineral

Amethyst Quartz

Silicon Dioxide (SiO2) with iron impurities

Hardness: 7 Mohs scale; Color: Pale lavender to deep purple; Luster: Vitreous/glassy; Crystal Structure: Hexagonal; Cleavage: None/Conchoidal fracture; Specific Gravity: 2.65

Hardness: 7 Mohs scale
Color: Pale lavender to deep purple
Luster: Vitreous/glassy

Identified May 9, 2026More mineral →

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Physical properties

Hardness: 7 Mohs scale; Color: Pale lavender to deep purple; Luster: Vitreous/glassy; Crystal Structure: Hexagonal; Cleavage: None/Conchoidal fracture; Specific Gravity: 2.65

Formation & geological history

Formed in hydrothermal veins or geodes within volcanic rock when silica-rich water enters gas cavities and crystallizes over millions of years, with color resulting from irradiation and iron impurities.

Uses & applications

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

Geological facts

Amethyst was considered a precious gemstone until large deposits were found in Brazil in the 1700s. The name comes from the Ancient Greek 'amethystos', meaning 'not intoxicated'.

Field identification & locations

Identified by its hexagonal crystal habit, purple hue, and lack of cleavage (it breaks like glass). Often found in Brazil, Uruguay, and various parts of the USA like Arizona.

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