mineral
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Hardness: 7 (Mohs scale); Color: Purple to violet; Luster: Vitreous (glassy); Crystal Structure: Hexagonal/Trigonal; Cleavage: None; Specific Gravity: 2.65
- Hardness
- 7 (Mohs scale)
- 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 scale); Color: Purple to violet; Luster: Vitreous (glassy); Crystal Structure: Hexagonal/Trigonal; Cleavage: None; Specific Gravity: 2.65
Formation & geological history
Formed in hydrothermal veins or as linings in cavities (geodes) within igneous rocks, particularly volcanic basalts. The purple color is caused by irradiation of trivalent iron impurities.
Uses & applications
Widely used as a gemstone in jewelry, for decorative household items, as a healing crystal in metaphysical practices, and as a popular mineral specimen for collectors.
Geological facts
Amethyst is the most valuable variety of quartz. Its name comes from the Ancient Greek 'amethystos', meaning 'not intoxicated', due to a belief that the stone protected its owner from drunkenness.
Field identification & locations
Identify by its characteristic purple color and hexagonal habit if uncut. Common in Brazil, Uruguay, and Africa. Look for clear, vibrant purple areas and natural quartz fractures.
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