mineral
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Hardness: 7 on Mohs scale. Color: Violet to dark purple. Luster: Vitreous/glassy. Crystal structure: Hexagonal/trigonal. Cleavage: None (conchoidal fracture). Specific gravity: ~2.65.
- Hardness
- 7 on Mohs scale
- Color
- Violet to dark purple
- Luster
- Vitreous/glassy
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Physical properties
Hardness: 7 on Mohs scale. Color: Violet to dark purple. Luster: Vitreous/glassy. Crystal structure: Hexagonal/trigonal. Cleavage: None (conchoidal fracture). Specific gravity: ~2.65.
Formation & geological history
Forms in hydrothermal veins and cavities (geodes) within volcanic rocks when silica-rich fluids cool and crystallize in the presence of trace amounts of ferric iron (Fe3+) combined with natural irradiation.
Uses & applications
Widely used as a gemstone in jewelry (rings, necklaces, earrings), ornamental carvings, crystal healing, and as decorative geode/cluster display specimens for collectors.
Geological facts
Amethyst is the official birthstone for February. Ancient Greeks believed wearing or drinking from cups made of amethyst would prevent intoxication, which is where its name originates (Greek 'amethystos' meaning 'not intoxicated').
Field identification & locations
Identified by its distinctive purple color, hardness (scratches glass, cannot be scratched by steel knife), and crystal form. Major sources include Brazil, Uruguay, Madagascar, Zambia, and Russia.
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