mineral
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Hardness: 7 Mohs; Color: Purple to violet; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65
- Hardness
- 7 Mohs
- Color
- Purple to 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 Mohs; Color: Purple to violet; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65
Formation & geological history
Forms in hydrothermal veins or volcanic geodes when silica-rich fluids cool and crystallize in the presence of trace iron and natural irradiation. Most common in basaltic rocks.
Uses & applications
Extensively used in jewelry (faceting and cabochons), ornamental turnings, and as a popular collector specimen for metaphysical and aesthetic purposes.
Geological facts
The name comes from the Greek word 'amethystos', meaning 'not intoxicated', as ancient Greeks believed the stone could prevent drunkenness.
Field identification & locations
Identify by its distinctive purple color and lack of cleavage. Often found in Brazil, Uruguay, and Zambia. Tumbled pieces like this are common in rock shops.
More like this
Other mineral specimens
Sandstone (with potential mineral staining/concretions)
Arenite (SiO2 based)
sedimentary
Soil with Mineral Detritus and Quartz Fragments
Regolith / Silicate Mineral Aggregate
sedimentary
Limonite / Goethite (Iron Ore Mineral nodule)
FeO(OH)·nH2O / FeO(OH)
mineral
Schist
Schist
Metamorphic
Septarian Pebble
Septarian nodule / Concretion
sedimentary
Potassium Feldspar (Orthoclase)
Orthoclase (KAlSi3O8)
mineral