mineral

Amethyst

Silicon Dioxide with trace Iron (SiO2 + Fe3+)

Hardness: 7 on Mohs scale; Color: Pale lavender to deep violet/purple; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: Pale lavender to deep violet/purple
Luster: Vitreous (glassy)

Identified March 7, 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 lavender to deep violet/purple; 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 volcanic geodes. The purple color is the result of natural irradiation and trace iron impurities within the quartz lattice. Geologic age varies significantly depending on the deposit (e.g., Brazil deposits are ~130 million years old, Cretaceous).

Uses & applications

Extensively used in jewelry (faceting and cabochons), ornamental carvings, crystal healing collections, and as decorative geode specimens for interior design.

Geological facts

Until the 19th century when large deposits were found in Brazil, Amethyst was considered one of the 'cardinal gems' and was as expensive as diamonds. The word comes from the Greek 'amethystos,' meaning 'not intoxicated,' as people believed it protected against drunkenness.

Field identification & locations

Identify in the field by its distinct purple hue, hexagonal crystal habit with pyramid-shaped terminations, and lack of cleavage. Commonly found in basaltic rocks in southern Brazil, Uruguay, and various locations in Arizona, Canada, and Africa.

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