mineral

Amethyst

SiO2 (Silicon Dioxide with Iron impurities)

Hardness: 7 on Mohs scale; Color: Pale lilac to deep purple; Luster: Vitreous (glassy); 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 (glassy)

Identified March 20, 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 (glassy); Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Formed in cavities or geodes of igneous volcanic rocks through hydrothermal processes where silica-rich fluids and iron impurities are present. Formation can occur over millions of years as magma cools and groundwater trickles through rock cavities.

Uses & applications

Predominantly used as a gemstone in jewelry (rings, necklaces, earrings) and as decorative mineral specimens for collectors and interior design. Historically used for amulets.

Geological facts

Amethyst's purple color is the result of irradiation, iron impurities, and the presence of trace elements. Its name comes from the Ancient Greek 'amethystos', meaning 'not intoxicated', as it was believed to protect the wearer from drunkenness.

Field identification & locations

Identify by its characteristic purple hexoganol prisms and lack of cleavage. It is commonly found in Brazil (Rio Grande do Sul), Uruguay, Madagascar, and the United States (Arizona/North Carolina). Collectors look for deep 'Siberian' purple hues with red or blue flashes.

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