mineral

Amethyst

Silicon Dioxide (SiO2)

AI-generated identification · may be incorrect

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

Hardness: 7 on Mohs scale
Color: light to deep purple
Luster: Vitreous/glassy

Identified July 1, 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: light to deep purple; Luster: Vitreous/glassy; Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Formed in hydrothermal veins or cavities (geodes) of igneous and metamorphic rocks. The purple color comes from iron impurities and natural irradiation. Found in deposits ranging from Precambrian to Cenozoic eras.

Uses & applications

Primary use is in jewelry, gemstone cutting, and ornamental decoration. It is also a highly popular mineral for collectors and metaphysical use.

Geological facts

Until the 18th century, amethyst was included in the cardinal gemstones alongside diamond, ruby, emerald, and sapphire. Large deposits in Brazil discovered in the 1700s made it much more accessible.

Field identification & locations

Identify by its characteristic purple hue and inability to be scratched by a steel pocketknife. Commonly found in Brazil, Uruguay, Zambia, and Ontario. Collectors should look for saturated color and clarity.