mineral

Amethyst Geode

Amethyst (Silicon Dioxide, SiO2)

Hardness: 7.0 Mohs; Color: Purple to violet; Luster: Vitreous/Glassy; Crystal structure: Trigonal (Hexagonal prisms); Cleavage: None; Specific Gravity: 2.65

Hardness: 7
Color: Purple to violet
Luster: Vitreous/Glassy

Identified July 8, 2026More mineral →

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Physical properties

Hardness: 7.0 Mohs; Color: Purple to violet; Luster: Vitreous/Glassy; Crystal structure: Trigonal (Hexagonal prisms); Cleavage: None; Specific Gravity: 2.65

Formation & geological history

Formed in hydrothermal veins and basaltic geodes through the precipitation of silica from mineral-rich water in volcanic cavities. The purple color is caused by irradiation, iron impurities, and the presence of trace elements.

Uses & applications

Used widely in jewelry (faceted or cabochon), ornamental decoration, spiritual practices, and as a popular collector's specimen.

Geological facts

Amethyst is the birthstone for February. Its name comes from the Ancient Greek word 'amethystos', meaning 'not intoxicated', as Greeks believed the stone protected the wearer from drunkenness.

Field identification & locations

Identify in the field by the distinct purple hexagonal crystal points inside a dull, rock-like matrix. Common locations include Brazil, Uruguay, and Namibia. Collectors should look for deep purple color and clarity.