mineral

Amethyst

Amethyst (Silicon Dioxide, SiO2 + trace Fe3+)

Hardness: 7 (Mohs scale), Color: Purple to violet, Luster: Vitreous/Glassy, Crystal Structure: Hexagonal (trigonal), Cleavage: Indistinct, Specific Gravity: 2.65

Identified June 22, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale), Color: Purple to violet, Luster: Vitreous/Glassy, Crystal Structure: Hexagonal (trigonal), Cleavage: Indistinct, Specific Gravity: 2.65

Formation & geological history

Formed in hydrothermal veins or geodes within volcanic rocks where silica-rich solutions crystallize. Color is produced by irradiation of trace iron atoms in the quartz lattice.

Uses & applications

Primary use in jewelry as a semi-precious gemstone, ornamental decoration, and a popular collector's mineral.

Geological facts

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

Field identification & locations

Identify by its characteristic purple color, hexagonal crystal habit, and its ability to scratch glass. Found heavily in Brazil, Uruguay, and Africa.

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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