mineral

Amethyst

Silicon Dioxide (SiO2) with iron impurities

Hardness: 7 on the Mohs scale. Color: Pale lilac to deep purple. Luster: Vitreous. Crystal Structure: Hexagonal (trigonal). Cleavage: None (conchoidal fracture). Specific Gravity: 2.65.

Hardness: 7 on the Mohs scale
Color: Pale lilac to deep purple
Luster: Vitreous

Identified March 20, 2026More mineral →

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Physical properties

Hardness: 7 on the Mohs scale. Color: Pale lilac to deep purple. Luster: Vitreous. Crystal Structure: Hexagonal (trigonal). Cleavage: None (conchoidal fracture). Specific Gravity: 2.65.

Formation & geological history

Formed in hydrothermal veins or as linings within volcanic rock gas bubbles (geodes). The purple color results from irradiation of trivalent iron impurities. Found in rocks ranging from Precambrian to Cenozoic eras.

Uses & applications

Primarily used in jewelry (faceting and cabochons) and as decorative specimens for mineral collectors. Historically believed to prevent intoxication.

Geological facts

Amethyst was considered one of the 'cardinal gems' until large deposits were found in Brazil, making it more affordable. Its name comes from the Ancient Greek 'amethystos', meaning 'not drunk'.

Field identification & locations

Identify by its purple color and ability to scratch glass but not topaz. Look for it in basaltic geodes or quartz veins. Common global locations include Brazil, Uruguay, and Zambia.

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