mineral

Amethyst

Silicon Dioxide (SiO2) with iron impurities

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

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

Identified July 5, 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, violet, or lavender; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Formed in hydrothermal veins or volcanic geodes when silica-rich water cools and crystallizes. The purple color comes from irradiation of iron impurities within the quartz lattice. Most specimens are millions of years old.

Uses & applications

Extensively used in jewelry (faceting and cabochons), ornamental carvings, and widely collected as mineral specimens or for metaphysical belief systems.

Geological facts

Amethyst was considered one of the five cardinal gemstones until large deposits were found in Brazil. The name comes from the Ancient Greek word 'amethystos', meaning 'not intoxicated', as it was believed to protect the wearer from drunkenness.

Field identification & locations

Identify by its purple hue and hexagonal crystal habit. Found globally with major deposits in Brazil, Uruguay, Zambia, and Canada. Collectors should look for deep uniform color and high clarity.