mineral

Amethyst (Tumbled)

Silicon Dioxide with iron impurities (SiO2)

Hardness: 7 on Mohs scale; Color: Purple, violet, or lavender with white quartz bands; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: Purple, violet, or lavender with white quartz bands
Luster: Vitreous (glassy)

Identified April 9, 2026More mineral →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Formation & geological history

Formed in hydrothermal veins or as linings in geodes within igneous volcanic rocks. The purple color is caused by irradiation of trivalent iron impurities (Fe3+). Found in deposits ranging from Precambrian to Cenozoic ages.

Uses & applications

Mostly used in jewelry, lapidary arts, decorative items, and by mineral collectors. In industry, high-quality quartz is used in electronics and timekeeping, though amethyst is typically kept for ornamentation.

Geological facts

Amethyst was considered a precious stone in ancient times, on par with diamonds and rubies. The name comes from the Greek word 'amethystos', meaning 'not intoxicated', as it was believed to prevent drunkenness.

Field identification & locations

Identify by its distinct purple hue and ability to scratch glass. In the field, look for volcanic basalt regions. It is common in Brazil, Uruguay, and Africa. Collectors should look for deep, uniform color and transparency.

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