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 or as linings in geodes (amygdules) within volcanic rocks. The purple color is caused by the presence of iron and the effects of natural gamma radiation on the quartz lattice.
Uses & applications
Primarily used in jewelry, as gemstone specimens for collectors, and in decorative items or metaphysical practices.
Geological facts
Amethyst was considered a 'Precious Stone' alongside Diamond, Ruby, Emerald, and Sapphire until large deposits were found in Brazil in the 19th century.
Field identification & locations
Identify by its distinct purple hue, glass-like luster, and hexagonal crystal shapes. Often found in basaltic rocks or as loose crystals in alluvial deposits.
More like this
Other mineral specimens
Sandstone (with potential mineral staining/concretions)
Arenite (SiO2 based)
sedimentary
Schist
Schist
Metamorphic
Sandstone with Mineral Veining or Crust
Sedimentary Sandstone (mostly SiO2 with Fe2O3 tinting)
sedimentary
Potassium Feldspar (Orthoclase)
Orthoclase (KAlSi3O8)
mineral
Gypsum (variety Selenite or Alabaster)
Calcium sulfate dihydrate (CaSO4·2H2O)
Mineral
Nephrite Jade
Nephrite
Mineral/Rock