mineral

Amethyst

Silicon Dioxide (SiO2) with iron impurities

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

Identified March 24, 2026More mineral →

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Physical properties

Hardness: 7 (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 volcanic geodes when silicon-rich water precipitates in cavities. Color variation is caused by irradiation of trivalent iron (Fe3+) in the silica structure.

Uses & applications

Primary use is in jewelry (beads, faceted stones, cabochons) and as a decorative mineral for collectors and metaphysical practitioners.

Geological facts

Until the 18th century, amethyst was considered one of the five cardinal gemstones alongside diamonds, rubies, sapphires, and emeralds before large deposits were found in Brazil.

Field identification & locations

Identified by its distinctive purple hue and ability to scratch glass. Commonly found in Brazil, Uruguay, Zambia, and South Korea. Look for color zoning (darker/lighter bands) in natural specimens.

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