mineral

Amethyst

Silicon Dioxide with Iron impurities (SiO2)

Hardness: 7 on Mohs scale; Color: Pale lilac to deep purple; Luster: Vitreous (glassy); Crystal structure: Hexagonal/Trigonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Hardness: 7 on Mohs scale
Color: Pale lilac to deep purple
Luster: Vitreous (glassy)

Identified March 28, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Pale lilac to deep purple; Luster: Vitreous (glassy); Crystal structure: Hexagonal/Trigonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Formation & geological history

Formed in hydrothermal veins or as linings inside volcanic geodes. The purple color is caused by natural irradiation of trace amounts of iron within the crystal lattice. Most commercial specimens range from 50 to 150 million years old.

Uses & applications

Predominantly used in jewelry as a gemstone, lapidary arts, and as a popular mineral specimen for collectors. Traditionally used as 'birthstone' jewelry and in decorative carvings.

Geological facts

The name comes from the Ancient Greek word 'amethystos', meaning 'not intoxicated', as it was believed to protect the wearer from drunkenness. It was once considered one of the five cardinal gemstones alongside diamond and ruby.

Field identification & locations

Identify in the field by its purple hue, hexagonal prism shape (if terminated), and inability to be scratched by a steel knife. Commonly found in Brazil, Uruguay, and Thunder Bay, Canada. Collectors should look for deep color saturation and clarity.

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