mineral

Amethyst

Amethyst (Silicon Dioxide - SiO2 with Iron impurities)

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

Hardness: 7 (Mohs scale)
Color: Pale lilac to deep purple
Luster: Vitreous/Glassy

Identified April 12, 2026More mineral →

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Physical properties

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

Formation & geological history

Formed in hydrothermal veins and basaltic geodes. Its purple color comes from gamma irradiation and the presence of trace iron impurities within the quartz crystal lattice.

Uses & applications

Primary use is in jewelry (faceted stones, cabochons) and as decorative specimens for mineral collectors. Also used in spiritual and holistic practices.

Geological facts

Until the discovery of large deposits in Brazil in the 19th century, amethyst was as expensive as ruby and emerald. It is the birthstone for February.

Field identification & locations

Identify by its distinct purple color and inability to be scratched by a steel knife. Look for conchoidal (shell-like) fractures rather than flat cleavage planes. Found worldwide, notably in Brazil, Uruguay, and Zambia.

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