mineral

Amethyst

Amethyst (Silicon Dioxide - SiO2 with ferric iron impurities)

Hardness: 7.0 Mohs; Color: Pale lilac to deep purple; Luster: Vitreous (glass-like); Crystal Structure: Hexagonal (rhombohedral); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7
Color: Pale lilac to deep purple
Luster: Vitreous (glass-like)

Identified March 24, 2026More mineral →

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Physical properties

Hardness: 7.0 Mohs; Color: Pale lilac to deep purple; Luster: Vitreous (glass-like); Crystal Structure: Hexagonal (rhombohedral); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Forms in hydrothermal veins and basaltic geodes through the deposition of silica from mineral-rich water. Its purple color results from gamma irradiation and the presence of trace iron impurities (Fe3+) in the quartz crystal lattice.

Uses & applications

Predominantly used as a gemstone in jewelry (rings, necklaces, earrings) and as decorative specimens or geodes for home decor and mineral collecting.

Geological facts

Until the 18th century, amethyst was included in the cardinal gemstones alongside diamond, ruby, sapphire, and emerald. Ancient Greeks believed it could prevent intoxication; the word 'amethyst' comes from the Greek 'amethystos' meaning 'not intoxicated'.

Field identification & locations

Identify in the field by its hexagonal crystal habit, purple hue, and inability to be scratched by a steel pocket knife. Commonly found in Brazil, Uruguay, Madagascar, and the United States (specifically Arizona and North Carolina).

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