mineral
Amethyst on Basalt Matrix
Crystalline Silicon Dioxide (SiO2) with iron impurities
Hardness: 7.0 (Mohs scale), Color: light to deep purple and translucent clear, Luster: Vitreous (glass-like), Crystal System: Hexagonal/Trigonal, Conchoidal fracture
- Hardness
- 7
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Physical properties
Hardness: 7.0 (Mohs scale), Color: light to deep purple and translucent clear, Luster: Vitreous (glass-like), Crystal System: Hexagonal/Trigonal, Conchoidal fracture
Formation & geological history
Formed in volcanic cavities or geodes. Iron-rich silica-bearing fluids crystallized within gas bubbles in basaltic lava over millions of years, with natural radiation causing the purple hue.
Uses & applications
Widely used for jewelry, lapidary art, spiritual healing practices, and as a popular collector's specimen.
Geological facts
Amethyst was considered a precious stone comparable to diamond until massive deposits were discovered in Brazil in the 19th century. Its name comes from the Greek word 'amethystos', meaning 'not intoxicated'.
Field identification & locations
Identified by its purple hexagonal crystals growing on a green/black basalt or chalcedony matrix. Commonly found in Brazil, Uruguay, and Madagascar. Collectors look for deep color and clarity.
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