mineral
Amethyst
Quartz (Silicon Dioxide with iron impurities), SiO2
Hardness: 7 on Mohs scale; Color: Purple to deep violet; Luster: Vitreous; Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65
- Hardness
- 7 on Mohs scale
- Color
- Purple to deep violet
- Luster
- Vitreous
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Physical properties
Hardness: 7 on Mohs scale; Color: Purple to deep violet; Luster: Vitreous; Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65
Formation & geological history
Formed in hydrothermal veins or geodes within igneous rocks when silica-rich water cools. The purple color is caused by trace amounts of iron and natural irradiation. Found in ages ranging from Precambrian to Cenozoic.
Uses & applications
Primarily used as a gemstone in jewelry, for decorative carvings, and as a popular specimen for mineral collectors and metaphysical practitioners.
Geological facts
Amethyst is the birthstone for February. The name comes from the Ancient Greek 'amethystos', meaning 'not intoxicated', as it was believed to prevent drunkenness.
Field identification & locations
Identify by its characteristic purple color and hexagonal crystal facets (if present). It can be found globally with major deposits in Brazil, Uruguay, Zambia, and Arizona. It will scratch glass but cannot be scratched by a steel knife.
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