Amethyst

Physical Properties

Hardness: 7 on the Mohs scale; Color: Purple, violet, to lavender; Luster: Vitreous; Crystal Structure: Trigonal (hexagonal prisms); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65.

Formation & Geological History

Formed in hydrothermal veins or as linings within geodes inside volcanic basalt. The purple color is caused by natural irradiation of trace iron impurities within the quartz crystal lattice. Age varies by location, with many specimens from Brazil being roughly 130 million years old.

Uses & Applications

Primarily used in jewelry (faceting and cabochons), ornamental decorative items, and as a popular specimen for mineral collectors and practitioners of holistic healing.

Geological Facts

Amethyst is the birthstone for February. Its name comes from the Ancient Greek word 'amethystos', meaning 'not intoxicated', as it was once believed to prevent drunkenness. Large geodes can reach heights of several meters.

Field Identification & Locations

Identify in the field by its distinct purple hue and crystal habit; look for geodes in volcanic regions. It will scratch glass but cannot be scratched by a steel knife. Common locations include Brazil, Uruguay, Zambia, and South Korea.

Identified on: 4/13/2026

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