Rock Identifier
Amethyst (Silicon Dioxide (SiO2) with iron impurities) — mineral
mineral

Amethyst

Silicon Dioxide (SiO2) with iron impurities

Hardness: 7 (Mohs scale); Color: Pale lilac to deep reddish-purple; Luster: Vitreous; Crystal structure: Hexagonal/Trigonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Hardness
7 (Mohs scale)
Color
Pale lilac to deep reddish-purple
Luster
Vitreous
Identified More mineral

Identify your own rocks.

Get a report just like this from any photo, free.

Physical properties

Hardness: 7 (Mohs scale); Color: Pale lilac to deep reddish-purple; Luster: Vitreous; Crystal structure: Hexagonal/Trigonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Formation & geological history

Formed in hydrothermal veins and cavities (geodes) of igneous rocks. Its purple color is the result of irradiation and the presence of trace elements of iron and other transition metals. Most commercial deposits range from thousands to millions of years old.

Uses & applications

Primary use is in jewelry (beads, rings, pendants) and as decorative specimens for collectors. It is the birthstone for February and is highly valued in metaphysical practices.

Geological facts

Amethyst was considered a 'Cardinal gem' alongside diamond, sapphire, ruby, and emerald until large deposits were found in Brazil. The name comes from the Greek 'amethystos,' meaning 'not intoxicated,' as it was believed to prevent drunkenness.

Field identification & locations

Identify by its characteristic purple zoning, lack of cleavage, and ability to scratch glass. Commonly found in Brazil, Uruguay, Zambia, and Canada. In the field, look for hexagonal prismatic crystals inside basaltic vugs or as part of quartz-rich veins.