mineral

Amethyst

Silicon Dioxide (SiO2) with iron impurities

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

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

Identified June 7, 2026More mineral →

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: Pale violet to deep purple; Luster: Vitreous; Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Formed in hydrothermal veins or geodes within igneous rocks. Purple coloration is caused by irradiation of iron impurities in the quartz lattice.

Uses & applications

Primary use in jewelry, decorative items, and as a popular collector specimen. Historically believed to prevent intoxication.

Geological facts

Amethyst was once considered one of the 'cardinal gems' along with diamond, ruby, and emerald until large deposits were found in Brazil.

Field identification & locations

Look for purple crystalline quartz clusters. Common in Brazil, Uruguay, and South Korea. Collectors should look for deep uniform color and lack of visible inclusions.