mineral

Amethyst

Amethyst (Quartz variety), Silicon Dioxide (SiO2)

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

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

Identified March 11, 2026More mineral →

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Physical properties

Hardness: 7 on the Mohs scale; Color: Pale lavender 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 hollow cavities (geodes) within volcanic rocks through the crystallization of silica-rich solutions. The purple color is caused by irradiation of trivalent iron impurities (Fe3+) in the crystal lattice.

Uses & applications

Primarily used as a semi-precious gemstone in jewelry, decorative carvings, and as a popular specimen for mineral collectors. Also used in alternative healing practices.

Geological facts

Until the discovery of massive deposits in Brazil in the 19th century, amethyst was considered one of the 'Cardinal Gems' and was as expensive as rubies or emeralds. It is the birthstone for February and the 6th wedding anniversary gem.

Field identification & locations

Identify in the field by its distinct purple color, hexagonal crystal points, and lack of cleavage. It is commonly found in Brazil (Rio Grande do Sul), Uruguay, and parts of the United States like Arizona and North Carolina. Collectors look for deep saturation and clear transparency.

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