mineral
Amethyst (Rough Quartz)
Silicon Dioxide (SiO2 with Iron impurities)
Hardness: 7 on Mohs scale; Color: Pale lavender to deep violet; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (trigonal); Cleavage: Indistinct/Conchoidal fracture; Specific Gravity: 2.65
- Hardness
- 7 on Mohs scale
- Color
- Pale lavender to deep violet
- Luster
- Vitreous (glassy)
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Physical properties
Hardness: 7 on Mohs scale; Color: Pale lavender to deep violet; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (trigonal); Cleavage: Indistinct/Conchoidal fracture; Specific Gravity: 2.65
Formation & geological history
Formed in hydrothermal veins or cavities (geodes) when silica-rich water precipitates quartz. The purple color comes from irradiation of iron impurities over millions of years.
Uses & applications
Widely used in jewelry (faceting and cabochons), crystal healing practices, as interior decor, and for mineral collection specimens.
Geological facts
Amethyst was once considered one of the five cardinal gemstones alongside diamonds and rubies until large deposits were found in Brazil in the 1700s, making it more common.
Field identification & locations
Identify by its purple hue, lack of cleavage, and ability to scratch glass. Found commonly in Brazil, Uruguay, Zambia, and Ontario, Canada (notably the Thunder Bay area).
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metamorphic
Gypsum (variety Selenite or Alabaster)
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Mineral
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Mineral/Rock
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