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

Amethyst (Variety of Quartz)

Silicon Dioxide (SiO2) with iron impurities

Hardness: 7 (Mohs scale); Color: Purple/Violet; Luster: Vitreous/Glassy; Crystal structure: Hexagonal (trigonal); Cleavage: None (Conchoidal fracture); Specific gravity: 2.65

Hardness
7 (Mohs scale)
Color
Purple/Violet
Luster
Vitreous/Glassy
Identified More mineral

Identify your own rocks.

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

Physical properties

Hardness: 7 (Mohs scale); Color: Purple/Violet; Luster: Vitreous/Glassy; Crystal structure: Hexagonal (trigonal); Cleavage: None (Conchoidal fracture); Specific gravity: 2.65

Formation & geological history

Formed in hydrothermal veins and volcanic cavities (geodes) when silica-rich solutions cool. The purple color is caused by trace amounts of iron influenced by natural irradiation from the surrounding rock.

Uses & applications

Primary use in jewelry as a gemstone, lapidary arts, and highly valued as decorative display specimens by collectors and the metaphysical community.

Geological facts

Amethyst was considered one of the 'Cardinal Gems' until large deposits were found in Brazil. Its name comes from the Ancient Greek 'amethystos', meaning 'not intoxicated', due to a belief that the stone protected its owner from drunkenness.

Field identification & locations

Identify in the field by its distinct purple color, lack of cleavage, and ability to scratch glass but not topaz. Commonly found in Brazil, Uruguay, Madagascar, and Arizona, USA.