mineral

Amethyst

Silicon Dioxide with Iron impurities (SiO2 + Fe3+)

Hardness: 7 on Mohs scale; Color: Pale lavender to deep violet; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: Pale lavender to deep violet
Luster: Vitreous (glassy)

Identified April 11, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Pale lavender to deep violet; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Formed in hydrothermal veins or geodes when silica-rich water cools and crystallizes. The purple color is caused by gamma irradiation of trace iron impurities within the quartz crystal lattice.

Uses & applications

Extensively used in jewelry (facets and cabochons), ornamental carvings, and by collectors as clusters or tumbled stones. Also used in spiritual/metaphysical practices.

Geological facts

Until the 18th century, amethyst was included in the cardinal gemstones alongside diamond, sapphire, ruby, and emerald. Huge deposits found in Brazil lowered its market rarity, but deep purple 'Siberian' grade specimens remain highly prized.

Field identification & locations

Identify by its distinctive purple color and lack of cleavage. In the field, look for volcanic rock cavities (geodes). Major sources include Brazil, Uruguay, Zambia, and Ontario, Canada.

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