mineral
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Hardness: 7 (Mohs scale); Color: Pale violet to deep purple; Luster: Vitreous; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65
- Hardness
- 7 (Mohs scale)
- Color
- Pale violet to deep purple
- Luster
- Vitreous
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Physical properties
Hardness: 7 (Mohs scale); Color: Pale violet to deep purple; Luster: Vitreous; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65
Formation & geological history
Forms in hydrothermal veins and basaltic geodes through the cooling of silica-rich solutions under moderate temperatures and pressures. Its color is derived from irradiation and iron impurities in the quartz structure.
Uses & applications
Primarily used as a gemstone in jewelry, for decorative carvings, and as a popular specimen for mineral collectors and crystal healers.
Geological facts
Amethyst was once considered as valuable as diamonds and rubies until large deposits were discovered in Brazil in the 1700s. Its name comes from the Greek word 'amethystos', meaning 'not intoxicated'.
Field identification & locations
Identified by its distinctive purple hue and hexagonal crystal system if terminated. In the field, look for conchoidal (shell-like) fractures and the ability to scratch glass but not topaz. Found globally, specifically in Brazil, Uruguay, and Namibia.
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