mineral

Amethyst

Amethyst (SiO2 with iron impurities)

AI-generated identification · may be incorrect

Hardness: 7 on Mohs scale; Color: Purple to deep violet; Luster: Vitreous; Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: Purple to deep violet
Luster: Vitreous

Identified May 19, 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 on Mohs scale; Color: Purple to deep violet; Luster: Vitreous; Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Formed in hydrothermal veins or as linings in geodes. The purple color is caused by irradiation of iron impurities within the silicon dioxide crystal lattice. Common in volcanic rocks.

Uses & applications

Extensively used in jewelry (faceted or cabochon), as a decorative gemstone, and highly popular among mineral collectors.

Geological facts

Amethyst was considered one of the five cardinal gemstones until large deposits were found in Brazil. Its name comes from the Ancient Greek 'amethystos', meaning 'not intoxicated'.

Field identification & locations

Identify by its distinct purple hue and quartz crystal habit. Commonly found in Brazil, Uruguay, and South Korea. Collectors should look for deep, uniform color and transparency.