mineral

Amethyst

Quartz (Silicon Dioxide with iron impurities), SiO2

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

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

Identified July 21, 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 (Mohs scale); Color: Purple, violet, pale lavender; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Forms in hydrothermal veins and hollow rocks (geodes) when silica-rich water cools. The purple color is caused by natural irradiation of trace iron impurities within the quartz lattice. Geologic age varies based on locality.

Uses & applications

Extensively used in jewelry, as decorative display pieces, for lapidary work, and among mineral collectors.

Geological facts

Amethyst was considered a Cardinal Gem until the 18th century, ranking alongside diamonds and rubies in value until large deposits were found in Brazil. Its name comes from the Ancient Greek 'amethystos', meaning 'not intoxicated'.

Field identification & locations

Identified by its purple color and typical quartz crystal habit (6-sided prisms) or conchoidal fracture. Common locations include Brazil, Uruguay, Zambia, and South Korea. Look for hexagonal points and characteristic growth striations.

Other mineral specimens

See all

Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

sedimentary

Schist

Metamorphic

Sandstone with Mineral Veining or Crust

Sedimentary Sandstone (mostly SiO2 with Fe2O3 tinting)

sedimentary

Potassium Feldspar (Orthoclase)

Orthoclase (KAlSi3O8)

mineral

Gypsum (variety Selenite or Alabaster)

Calcium sulfate dihydrate (CaSO4·2H2O)

Mineral

Nephrite Jade

Nephrite

Mineral/Rock