gemstone

Amethyst

Quartz (Silicon Dioxide, SiO2)

Hardness: 7 on the Mohs scale. Color: Purple, violet, or pale lilac. Luster: Vitreous (glassy). Crystal structure: Trigonal (hexagonal system). Cleavage: None, exhibits conchoidal fracture. Specific gravity: 2.65.

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

Identified July 28, 2026More gemstone →

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

Formation & geological history

Formed in hydrothermal veins and gas cavities (vugs/geodes) within volcanic rocks, typically through the incorporation of trace iron impurities irradiated by natural radioactive decay over millions of years.

Uses & applications

Widely used in jewelry making as cut gemstones and beads, as well as in ornamental carvings, decorative pieces, and crystal healing collections.

Geological facts

Amethyst was once considered one of the cardinal precious gems alongside diamond, ruby, sapphire, and emerald until large deposits were discovered in Brazil.

Field identification & locations

Easily identified by its distinctive purple coloration and quartz hardness of 7, making it resistant to scratching by steel. Common sources include Brazil, Uruguay, Zambia, and the USA.