mineral
Amethyst
Silicon dioxide (SiO2) with iron impurities
Hardness: 7 (Mohs scale), Color: light to deep purple/lavender, Luster: Vitreous, Crystal structure: Trigonal (hexagonal prisms), Cleavage: None (conchoidal fracture)
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 (Mohs scale), Color: light to deep purple/lavender, Luster: Vitreous, Crystal structure: Trigonal (hexagonal prisms), Cleavage: None (conchoidal fracture)
Formation & geological history
Forms in hydrothermal veins and hollow cavities (geodes) within igneous rocks. The purple color is caused by natural irradiation of trace iron impurities replacing silicon in the crystal lattice.
Uses & applications
Predominantly used as a gemstone in jewelry, for decorative carvings, and as a popular specimen for mineral collectors and crystal healing enthusiasts.
Geological facts
The name comes from the ancient Greek 'amethystos', meaning 'not intoxicated', as it was believed to prevent drunkenness. Ancient Egyptians used it for intaglio engraved gems.
Field identification & locations
Identify by its distinct purple hue, glass-like luster, and lack of cleavage. It is famously found in massive quantities in Brazil and Uruguay, but also occurs in Arizona and Zambia.
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