mineral

Amethyst

Silicon Dioxide (SiO2) with iron impurities

Hardness: 7 on Mohs scale; Color: light pinkish-violet to deep purple; Luster: Vitreous; Crystal Structure: Trigonal; Cleavage: None (Conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: light pinkish-violet to deep purple
Luster: Vitreous

Identified March 13, 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: light pinkish-violet to deep purple; Luster: Vitreous; Crystal Structure: Trigonal; Cleavage: None (Conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Formed in hydrothermal veins and volcanic rocks (geodes). The color is produced by gamma irradiation of trivalent iron impurities and presence of trace elements. They can be found in rocks from the Precambrian to Cenozoic eras.

Uses & applications

Primary use is in jewelry (beads, faceted stones, cabochons) and as decorative specimens for collectors or metaphysical use.

Geological facts

Amethyst was considered a precious stone equal to diamond or ruby until the discovery of large deposits in Brazil in the 19th century. Its name comes from the Greek 'amethystos', meaning 'not intoxicated', due to an ancient belief it prevented drunkenness.

Field identification & locations

Identify by its purple color and hardness (it will scratch glass). When tumbled or beaded, look for natural inclusions or color zoning. Found globally, with major deposits in Brazil, Uruguay, 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