gemstone
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Hardness: 7 on the Mohs scale. Color: Violet to deep purple. Luster: Vitreous/glassy. Crystal system: Trigonal. Cleavage: None, fracture is conchoidal. Specific gravity: 2.65.
- Hardness
- 7 on the Mohs scale
- Color
- Violet to deep purple
- Luster
- Vitreous/glassy
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Physical properties
Hardness: 7 on the Mohs scale. Color: Violet to deep purple. Luster: Vitreous/glassy. Crystal system: Trigonal. Cleavage: None, fracture is conchoidal. Specific gravity: 2.65.
Formation & geological history
Forms inside hydrothermal veins and volcanic geodes when silica-rich fluids cool and crystallize in the presence of iron traces and natural irradiation.
Uses & applications
Widely used in fine and costume jewelry, cabochons, polished tumbled stones, beads, carved ornamental objects, and crystal healing collections.
Geological facts
Amethyst is the purple variety of quartz and the official birthstone for February. Ancient Greeks believed it could prevent intoxication and named it from 'amethystos', meaning 'not intoxicated'.
Field identification & locations
Identified by its distinct purple hue, glassy luster, and hardness (scratches glass, cannot be scratched by steel). Commonly found in Brazil, Uruguay, Madagascar, and Zambia.
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