mineral
Amethyst
Amethyst (Silicon Dioxide with iron impurities, SiO2)
Hardness: 7 on Mohs scale; Color: Purple, violet, to pale lavender; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65
- Hardness
- 7 on Mohs scale
- Color
- Purple, violet, to pale lavender
- Luster
- Vitreous (glassy)
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Physical properties
Hardness: 7 on Mohs scale; Color: Purple, violet, to pale lavender; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65
Formation & geological history
Formed in hydrothermal veins or inside volcanic geodes where silica-rich water precipitates in cavities. The purple color is caused by irradiation of iron impurities within the quartz structure. Typical age varies from millions to hundreds of millions of years.
Uses & applications
Primarily used in jewelry (faceting and cabochons), as decorative display specimens, and in metaphysical or alternative healing practices. High-quality specimens are prized by collectors.
Geological facts
Amethyst was once considered one of the 'Cardinal gems,' valued as highly as diamonds until large deposits were found in Brazil. The name comes from the Greek word 'amethystos,' meaning 'not intoxicated,' as it was believed to prevent drunkenness.
Field identification & locations
Identify by its distinct purple color, 6-sided hexagonal crystal points, and inability to be scratched by a steel blade. Commonly found in Brazil, Uruguay, Zambia, and South Korea. Collectors look for deep saturation of color and clarity.
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