mineral

Amethyst

Silicon Dioxide with Iron impurities (SiO2)

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

Hardness: 7 on the Mohs scale
Color: Pale lilac to deep royal purple
Luster: Vitreous (glass-like)

Identified March 16, 2026More mineral →

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Physical properties

Formation & geological history

Formed in hydrothermal veins or geodes within volcanic rocks when silica-rich water cools. The purple color is caused by irradiation of trivalent iron (Fe3+) impurities in the quartz structure. Most specimens are found in basaltic rocks from the Mesozoic era onwards.

Uses & applications

Primarily used as a gemstone in jewelry, for decorative carvings, and as a popular specimen for mineral collectors and crystal healing enthusiasts.

Geological facts

Amethyst was once considered a Cardinal Gem, ranking alongside Diamonds and Rubies in value until large deposits were discovered in Brazil. Its name comes from the Greek 'amethystos', meaning 'not intoxicated', due to an ancient belief it prevented drunkenness.

Field identification & locations

Identify by its distinct purple hue and prismatic crystal shape terminating in a point. It can be found in geodes in regions like Rio Grande do Sul (Brazil), Uruguay, and Ontario. To verify, check if it can scratch glass but cannot be scratched by a steel knife.

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