mineral

Amethyst

Silicon dioxide (Quartz variety), SiO2

AI-generated identification · may be incorrect

Hardness: 7 on Mohs scale; Color: Purple to violet; Luster: Vitreous (glassy); Crystal structure: Trigonal (hexagonal crystal system); Cleavage: None (exhibits conchoidal fracture); Specific gravity: 2.65

Hardness: 7 on Mohs scale
Color: Purple to violet
Luster: Vitreous (glassy)

Identified July 29, 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

Formation & geological history

Forms in hydrothermal veins and vugs, particularly within basaltic volcanic rocks, where silica-rich solutions cool and crystallize over millions of years.

Uses & applications

Widely used in gemstone jewelry, ornamental carvings, spiritual and holistic practices, and crystal collection.

Geological facts

Amethyst was once considered one of the cardinal gemstones of high value until extensive deposits were discovered in Brazil. Its purple color is caused by irradiation and trace amounts of iron substituting for silicon within the quartz lattice.

Field identification & locations

Identified by its distinct purple color, hexagonal crystal form, and conchoidal fracture. Commonly found in Brazil, Uruguay, Zambia, and the USA. This particular specimen has been cut and polished into a double-terminated quartz crystal shape.