mineral
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Hardness: 7 on Mohs scale; Color: Purple, violet, or lavender; Luster: Vitreous/glassy; Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); 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: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65
Formation & geological history
Forms in hydrothermal veins and hollow cavities (geodes) within igneous rocks. The purple color is caused by gamma irradiation of trivalent iron impurities within the quartz crystal lattice.
Uses & applications
Primarily used in jewelry making (faceted or cabochon), ornamental carvings, and as a popular semi-precious gemstone for mineral collectors.
Geological facts
Amethyst is the birthstone for February. Its name comes from the Ancient Greek 'amethystos', meaning 'not intoxicated', as it was believed to protect the wearer from drunkenness.
Field identification & locations
Identified by its purple color and typical quartz crystal habit. Commonly found in Brazil, Uruguay, Zambia, and South Korea. Collectors should look for intense color saturation and clarity.
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