mineral
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Hardness: 7 on Mohs scale; Color: Purple/Violet; Luster: Vitreous (glassy); Crystal Structure: Hexagonal/Trigonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65
- Hardness
- 7 on Mohs scale
- Color
- Purple/Violet
- Luster
- Vitreous (glassy)
Identified More mineral →
Explore Amethyst in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 7 on Mohs scale; Color: Purple/Violet; Luster: Vitreous (glassy); Crystal Structure: Hexagonal/Trigonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65
Formation & geological history
Forms in hydrothermal veins and basaltic geodes. Its purple color is caused by natural irradiation of trace amounts of trivalent iron (Fe3+) in its quartz structure. Often found in volcanic cavities.
Uses & applications
Extensively used in jewelry (faceting and cabochons), as decorative display specimens, and in metaphysical collecting.
Geological facts
Amethyst was considered a precious stone in antiquity, rivaling diamonds, until large deposits were found in Brazil. The name comes from the Greek 'amethystos', meaning 'not intoxicated', as it was believed to prevent drunkenness.
Field identification & locations
Identify by its six-sided prismatic crystals terminating in pyramids and its characteristic purple hue. Common in Brazil, Uruguay, Zambia, and South Korea. Collectors look for deep saturation and good clarity.
More like this
Other mineral specimens
Sandstone (with potential mineral staining/concretions)
Arenite (SiO2 based)
sedimentary
Sandstone with Mineral Veining or Crust
Sedimentary Sandstone (mostly SiO2 with Fe2O3 tinting)
sedimentary
Schist
Schist
Metamorphic
Potassium Feldspar (Orthoclase)
Orthoclase (KAlSi3O8)
mineral
Gypsum (variety Selenite or Alabaster)
Calcium sulfate dihydrate (CaSO4·2H2O)
Mineral
Nephrite Jade
Nephrite
Mineral/Rock