mineral

Amethyst

Quartz (SiO2)

Hardness: 7 on Mohs scale. Color: Purple to violet, sometimes with lighter or darker stripes. Luster: Vitreous (glassy). Crystal structure: Trigonal (hexagonal system), typically forming prismatic crystals terminating in a six-sided pyramid. Cleavage: None (conchoidal fracture). Specific gravity: 2.65.

Hardness: 7 on Mohs scale
Color: Purple to violet, sometimes with lighter or darker stripes
Luster: Vitreous (glassy)

Identified August 2, 2026More mineral →

Explore Amethyst in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Formation & geological history

Forms in hydrothermal veins and gas cavities (vesicles) in volcanic rocks, where silica-rich solutions cool and crystallize over long geological periods. Irradiation of trace iron impurities within the quartz lattice creates the purple color.

Uses & applications

Widely used in jewelry, ornamental carvings, decorative items, and metaphysical healing practices.

Geological facts

Ancient Greeks and Romans believed amethyst could prevent intoxication, which is where its name derived from the Greek 'amethystos' meaning 'not intoxicated'. It was once considered one of the cardinal gemstones alongside diamond, ruby, emerald, and sapphire.

Field identification & locations

Can be identified by its distinctive purple coloration and the hexagonal crystal habit with characteristic conchoidal fracture. Common localities include Brazil, Uruguay, Zambia, and the United States.