mineral
Amethyst
Quartz (Silicon Dioxide) SiO2 with iron impurities
Hardness: 7 on Mohs scale; Color: light to dark purple; Luster: vitreous; Crystal structure: hexagonal/trigonal; Cleavage: none (conchoidal fracture); Specific gravity: 2.65
- Hardness
- 7 on Mohs scale
- Color
- light to dark purple
- Luster
- vitreous
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Physical properties
Hardness: 7 on Mohs scale; Color: light to dark purple; Luster: vitreous; Crystal structure: hexagonal/trigonal; Cleavage: none (conchoidal fracture); Specific gravity: 2.65
Formation & geological history
Formed in hydrothermal veins or geodes within volcanic rock. The purple color results from irradiation, iron impurities, and the presence of trace elements. Age varies by location, often associated with Cretaceous basalt.
Uses & applications
Primarily used in jewelry (rings, necklaces), as decorative ornaments, and highly valued as a gemstone and collector's specimen.
Geological facts
Amethyst is the birthstone for February. The name comes from the Greek word 'amethystos', meaning 'not intoxicated', as it was anciently believed to prevent drunkenness.
Field identification & locations
Identify by its distinct purple hue and quartz crystal habit. Commonly found in Brazil, Uruguay, and Africa. Look for hexagonal crystal points and transparent to translucent clarity.
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