mineral

Amethyst (Rough)

Silicon Dioxide (SiO2) with iron impurities

Hardness: 7 on Mohs scale; Color: Purple, violet, or lavender; Luster: Vitreous (glassy) when fresh; Crystal structure: Trigonal/Hexagonal; Cleavage: None; Specific Gravity: 2.65.

Hardness: 7 on Mohs scale
Color: Purple, violet, or lavender
Luster: Vitreous (glassy) when fresh

Identified June 27, 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: Purple, violet, or lavender; Luster: Vitreous (glassy) when fresh; Crystal structure: Trigonal/Hexagonal; Cleavage: None; Specific Gravity: 2.65.

Formation & geological history

Formed in geodes within volcanic rocks (basalt) or in hydrothermal veins. The purple color is caused by irradiation of iron impurities within the quartz structure. Most specimens are from the Cretaceous period in South American deposits.

Uses & applications

Predominantly used for jewelry, lapidary arts, and as collectible interior decor. Historically used as an amulet against drunkenness.

Geological facts

Amethyst was once considered one of the 'Cardinal Gems' along with diamond and ruby until large deposits were found in Brazil, making it more accessible. Its name comes from the Greek 'amethystos', meaning 'not intoxicated'.

Field identification & locations

Identify by its distinctive purple hue and hexagonal crystal habits. Often found in Brazil, Uruguay, Zambia, and Ontario. Collectors look for deep 'Siberian' purple saturation with red or blue flashes.

Other mineral specimens

See all

Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

sedimentary

Schist

Metamorphic

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