mineral

Amethyst

Silicon Dioxide (SiO2) with Fe3+ impurities

Hardness: 7 (Mohs scale); Color: Purple, violet, or lavender; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (trigonal); Cleavage: None; Specific Gravity: 2.65

Hardness: 7 (Mohs scale)
Color: Purple, violet, or lavender
Luster: Vitreous (glassy)

Identified July 8, 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

Hardness: 7 (Mohs scale); Color: Purple, violet, or lavender; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (trigonal); Cleavage: None; Specific Gravity: 2.65

Formation & geological history

Formed in hydrothermal veins or as linings in geodes within igneous basalt cavities. The purple color is caused by gamma irradiation of trivalent iron impurities and crystal lattice defects.

Uses & applications

Primarily used in jewelry (faceting, cabochons), as ornamental specimens for decoration, and in metaphysical/holistic practices.

Geological facts

Amethyst is the birthstone for February. Its name comes from the Ancient Greek 'amethystos', meaning 'not intoxicated', due to a belief that the gem protected its owner from drunkenness.

Field identification & locations

Identify in the field by its purple hue, lack of cleavage, and hexagonal crystal habits. Common locations include Brazil, Uruguay, Zambia, and South Korea.