mineral

Amethyst (Druze)

Silicon Dioxide (SiO2) with iron impurities

Hardness: 7 on Mohs scale; Color: Pale lilac to deep purple; Luster: Vitreous (glassy); Crystal Structure: Hexagonal/Trigonal (terminating in six-sided pyramids); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

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

Identified May 3, 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 cavities (geodes) when silica-rich water precipitates crystals at low to moderate temperatures. Common in volcanic basalt pockets. Many commercial specimens are from the Cretaceous period.

Uses & applications

Used extensively in jewelry (as a semi-precious gemstone), decorative carvings, and as a popular specimen for mineral collectors. Also used in spiritual or metaphysical practices.

Geological facts

Amethyst is the purple variety of quartz; its color comes from irradiation of trivalent iron impurities. The name comes from the Greek 'amethystos', meaning 'not intoxicated', as it was once believed to prevent drunkenness.

Field identification & locations

Identify by its purple hue, hexagonal crystal points, and ability to scratch glass. Found globally, with major deposits in Brazil (Rio Grande do Sul) and Uruguay. Look for it in volcanic rock outcrops or inside rounded 'thunder egg' nodules.

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