mineral

Amethyst

Silicon dioxide with iron impurities (SiO2)

Hardness: 7 (Mohs scale); Color: Purple to violet; Luster: Vitreous (glassy); Crystal structure: Hexagonal/Trigonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65.

Hardness: 7 (Mohs scale)
Color: Purple to violet
Luster: Vitreous (glassy)

Identified January 22, 2026More mineral →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Hardness: 7 (Mohs scale); Color: Purple to violet; Luster: Vitreous (glassy); Crystal structure: Hexagonal/Trigonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65.

Formation & geological history

Formed in hydrothermal veins or as linings in geodes within igneous volcanic rocks. Its purple color is caused by irradiation of iron impurities within the silicon dioxide crystal lattice. It can be found in rocks from various geological ages, often associated with basaltic flows.

Uses & applications

Primarily used in jewelry (faceting, beads, and carvings like the bracelet shown), decorative ornamental objects, and as a popular mineral specimen for collectors.

Geological facts

Amethyst was considered a Cardinal Gem until the 18th century, ranked alongside diamonds and rubies in value until large deposits were found in Brazil. Its name comes from the Greek 'amethystos', meaning 'not intoxicated', as it was historically believed to prevent drunkenness.

Field identification & locations

Identify by its characteristic purple color and lack of cleavage (it breaks with curved, glass-like surfaces). In the field, look for purple crystals inside hollow spherical rocks (geodes). Major deposits are located in Brazil, Uruguay, Zambia, and Ontario, Canada.

Other mineral specimens

See all

Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

sedimentary

Epidote

Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)

metamorphic

Nephrite Jade

Nephrite

Mineral/Rock

Banded Gneiss (River Rock/Pebble)

Gneiss (specifically a banded variety often found as a river rock)

Metamorphic Rock

Green Apatite on Albite

Fluorapatite [Ca5(PO4)3F] on Albite [Na(AlSi3O8)]

mineral

Epidote

Epidote - Ca2(Al2,Fe3+)3(SiO4)3(OH)

mineral