mineral

Amethyst

Amethyst (Silicon Dioxide - SiO2 with impurities of Fe3+)

Hardness: 7 on the Mohs scale. Color: Pale violet to deep purple. Luster: Vitreous (glassy). Crystal structure: Trigonal/Hexagonal. Cleavage: None (conchoidal fracture). Specific gravity: 2.65.

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

Identified March 18, 2026More mineral →

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Physical properties

Hardness: 7 on the Mohs scale. Color: Pale violet to deep purple. Luster: Vitreous (glassy). Crystal structure: Trigonal/Hexagonal. Cleavage: None (conchoidal fracture). Specific gravity: 2.65.

Formation & geological history

Formed in hydrothermal veins or as linings of basaltic geodes. The purple color results from gamma irradiation of trace trivalent iron (Fe3+) in the quartz structure. These can range from millions to billions of years old.

Uses & applications

Primarily used in jewelry (faceting, cabochons, beads), as ornamental specimens for home decor, and in crystal healing practices. It is the birthstone for February.

Geological facts

The word 'amethyst' comes from the Greek 'amethystos', meaning 'not drunken', as ancient Greeks believed it protected the wearer from intoxication. Until the 18th century, it was considered one of the five cardinal gemstones alongside diamonds and rubies.

Field identification & locations

Identify in the field by its distinct purple hue, glass-like luster, and inability to be scratched by a steel knife (hardness). Common locations include Brazil (Rio Grande do Sul), Uruguay, Zambia, and Ontario, Canada.

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