mineral

Amethyst (Quartz)

Silicon Dioxide (SiO2) with iron impurities

Hardness: 7 on Mohs scale; Color: Purple, violet, or lavender; Luster: Vitreous (glass-like); Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Hardness: 7 on Mohs scale
Color: Purple, violet, or lavender
Luster: Vitreous (glass-like)

Identified April 15, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Purple, violet, or lavender; Luster: Vitreous (glass-like); Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Formation & geological history

Forms in hydrothermal veins and hollow cavities (geodes) within igneous rocks. The purple color is caused by irradiation of iron impurities within the crystal lattice.

Uses & applications

Primarily used in jewelry (as a semi-precious gemstone), decorative carvings, lapidary arts, and as a popular specimen for mineral collectors.

Geological facts

Amethyst is the birthstone for February. Ancient Greeks believed it could prevent intoxication; the word comes from the Greek 'amethystos', meaning 'not drunken'.

Field identification & locations

Identify in the field by its characteristic purple hue, 6-sided hexagonal prism terminations, and ability to scratch glass. Commonly found in Brazil, Uruguay, and parts of Arizona and Ontario.

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Arenite (SiO2 based)

sedimentary

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Nephrite Jade

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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