mineral

Amethyst

Silicon Dioxide (SiO2) with Fe3+ impurities

Hardness: 7 (Mohs scale), Color: Purple to violet, Luster: Vitreous (glassy), Crystal system: Trigonal/Hexagonal, Cleavage: None (conchoidal fracture), Specific Gravity: 2.65

Identified June 26, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale), Color: Purple to violet, Luster: Vitreous (glassy), Crystal system: Trigonal/Hexagonal, Cleavage: None (conchoidal fracture), Specific Gravity: 2.65

Formation & geological history

Formed in hydrothermal veins and cavities (geodes) of igneous rocks when silica-rich water deposits crystals. The purple color is caused by trace amounts of iron and natural irradiation over millions of years.

Uses & applications

Predominantly used as a gemstone in jewelry (rings, necklaces), as decorative display pieces (cathedrals/geodes), and as a popular specimen for mineral collectors.

Geological facts

Amethyst was once considered one of the 'Cardinal Gems' alongside diamond and ruby, holding high value until large deposits were found in Brazil in the 19th century. Its name comes from the Greek 'amethystos', meaning 'not intoxicated'.

Field identification & locations

Identify by its distinct purple hexagonal crystals and the lack of cleavage. Commonly found in Brazil, Uruguay, and Madagascar. Collectors look for deep saturation of color and clarity of the crystal points.

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