mineral

Amethyst

Silicon Dioxide (SiO2)

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

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

Identified May 24, 2026More mineral →

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; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Formed in silica-rich hydrothermal veins and volcanic cavities (geodes) when iron and other trace minerals are irradiated within the quartz crystal during formation.

Uses & applications

Used extensively in jewelry (rings, necklaces, earrings), as ornamental display pieces, and in the lapidary arts. It is also the traditional birthstone for February.

Geological facts

The name comes from the Greek word 'amethystos', meaning 'not intoxicated', as ancient Greeks believed it protected the wearer from drunkenness. The purple color is caused by trace amounts of iron and natural irradiation.

Field identification & locations

Identified by its distinctive purple hue and hardness (it will scratch glass). Most commercial specimens come from Brazil or Uruguay. In the field, look for hexagonal prisms with pyramidal terminations in volcanic rocks.