mineral
Amethyst
Silicon Dioxide (SiO2) with trace Iron (Fe)
Hardness: 7 on Mohs scale; Color: Purple, violet, or lavender; Luster: Vitreous (glassy); Crystal structure: Trigonal (Hexagonal habit); Cleavage: None; Specific gravity: 2.65
- Hardness
- 7 on Mohs scale
- Color
- Purple, violet, or lavender
- Luster
- Vitreous (glassy)
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Physical properties
Hardness: 7 on Mohs scale; Color: Purple, violet, or lavender; Luster: Vitreous (glassy); Crystal structure: Trigonal (Hexagonal habit); Cleavage: None; Specific gravity: 2.65
Formation & geological history
Formed in hydrothermal veins and basaltic cavities (geodes) when silica-rich water precipitates quartz over millions of years. The purple color is caused by natural irradiation of trace iron impurities.
Uses & applications
Predominantly used as a gemstone in jewelry, for decorative crystal specimens, and in metaphysical practices.
Geological facts
Amethyst was considered a Cardinal Gem until the 18th century, ranking alongside diamonds and rubies in value until large deposits were found in Brazil. The name comes from the Greek word 'amethystos', meaning 'not intoxicated'.
Field identification & locations
Identify by its purple hue, hexagonal prismatic crystal shape, and conchoidal fracture. Commonly found in Brazil, Uruguay, Zambia, and Ontario. Collectors look for deep saturation and clarity.
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