mineral

Amethyst

Amethyst (Silicon Dioxide, SiO2 with Iron impurities)

Hardness: 7 (Mohs scale); Color: Purple, violet, to deep reddish-purple; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65.

Hardness: 7 (Mohs scale)
Color: Purple, violet, to deep reddish-purple
Luster: Vitreous (glassy)

Identified May 5, 2026More mineral →

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Physical properties

Formation & geological history

Formed in hydrothermal veins and basaltic geodes. The purple color comes from gamma irradiation of trace trivalent iron (Fe3+) in the quartz crystal structure as it grows from silica-rich groundwater. Often found in volcanic cavities.

Uses & applications

Predominantly used as a gemstone in jewelry, for decorative items, and as a popular specimen for mineral collectors and practitioners of crystal healing.

Geological facts

Amethyst is the birthstone for February. The name comes from the Ancient Greek 'amethystos', meaning 'not intoxicated', as it was believed to protect its owner from drunkenness.

Field identification & locations

Look for purple pyramidal crystal terminations on a white to gray matrix. It is commonly found in Brazil, Uruguay, Madagascar, and the United States (notably Arizona and Georgia). Identification can be confirmed by its hardness and absence of cleavage.

Other mineral specimens

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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