mineral

Amethyst

Silicon Dioxide (SiO2) with iron impurities

Hardness: 7 (Mohs scale); Color: Purple, violet, or lavender; Luster: Vitreous/Glassy; Crystal structure: Trigonal; Cleavage: None/Conchoidal fracture; Specific gravity: 2.65

Hardness: 7 (Mohs scale)
Color: Purple, violet, or lavender
Luster: Vitreous/Glassy

Identified April 4, 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, violet, or lavender; Luster: Vitreous/Glassy; Crystal structure: Trigonal; Cleavage: None/Conchoidal fracture; Specific gravity: 2.65

Formation & geological history

Formed in hydrothermal veins and basaltic geodes. The purple color comes from irradiation of iron impurities within the quartz crystal lattice. Found in rocks ranging from millions to over a billion years old.

Uses & applications

Mostly used for jewelry (faceted or cabochon), decorative ornaments, crystal healing, and as a popular specimen for mineral collectors.

Geological facts

Amethyst was considered a 'Cardinal Gem' until the 18th century, ranking alongside diamond and ruby in value until large deposits were found in Brazil. The name comes from the Greek word 'amethystos', meaning 'not intoxicated'.

Field identification & locations

Identify by its characteristic purple color and hexagonal crystal faces (if not tumbled). It can be found globally with major deposits in Brazil and Uruguay. Collectors should look for deep color saturation and clarity.

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