mineral

Amethyst

Silicon Dioxide (SiO2) with iron impurities

Hardness: 7 on Mohs scale; Color: Deep purple to pale lavender; Luster: Vitreous (glassy); Crystal Structure: Hexagonal/Trigonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: Deep purple to pale lavender
Luster: Vitreous (glassy)

Identified March 20, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Deep purple to pale lavender; Luster: Vitreous (glassy); Crystal Structure: Hexagonal/Trigonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Formed in hydrothermal veins or geodes within volcanic rocks where silica-rich fluids crystallize. The purple color is caused by irradiation of trivalent iron impurities in the quartz structure. Most specimens date from several million to hundreds of millions of years old.

Uses & applications

Primarily used as a gemstone in jewelry (rings, necklaces, earrings) and as decorative specimens or 'healing stones' in metaphysical practices. Historically used in royal crowns.

Geological facts

Ancient Greeks believed amethyst could prevent intoxication; the name comes from 'amethystos,' meaning 'not drunken.' It is the birthstone for February and the official state gemstone of South Carolina.

Field identification & locations

Identify in the field by its purple color, hardness (it will scratch glass), and lack of cleavage. Commonly found in Brazil, Uruguay, Madagascar, and the United States (Arizona/North Carolina).

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