mineral

Amethyst

Silicon Dioxide with iron impurities (SiO2)

Hardness: 7 on Mohs scale; Color: Pale lilac to deep purple; Luster: Vitreous (glass-like); Crystal structure: Hexagonal/Trigonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Hardness: 7 on Mohs scale
Color: Pale lilac to deep purple
Luster: Vitreous (glass-like)

Identified April 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 on Mohs scale; Color: Pale lilac to deep purple; Luster: Vitreous (glass-like); Crystal structure: Hexagonal/Trigonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Formation & geological history

Formed in hydrothermal veins or cavities (geodes) of igneous rocks when silica-rich water cools. The purple color is caused by irradiation of trivalent iron (Fe3+). Found in volcanic rocks ranging from prehistoric to modern eras.

Uses & applications

Predominantly used for jewelry, lapidary arts, spiritual/metaphysical collecting, and as decorative interior specimens.

Geological facts

Amethyst was considered a 'Precious Stone' until the 18th century when large deposits were found in Brazil. Its name comes from the Greek 'amethystos', meaning 'not intoxicated', as it was believed to prevent drunkenness.

Field identification & locations

Identify by its purple color and hexagonal prism crystal habits. Commonly found in Brazil, Uruguay, and Zambia. Collectors look for deep saturation of purple and lack of visible inclusions.

Other mineral specimens

See all

Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

sedimentary

Schist

Metamorphic

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