mineral

Amethyst

SiO2 (Silicon Dioxide with iron impurities)

Hardness: 7 on the Mohs scale; Color: purple to violet; Luster: vitreous (glassy); Crystal structure: hexagonal/trigonal; Cleavage: none (conchoidal fracture); Specific gravity: 2.65

Hardness: 7 on the Mohs scale
Color: purple to violet
Luster: vitreous (glassy)

Identified July 6, 2026More mineral →

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Physical properties

Hardness: 7 on the Mohs scale; Color: purple to violet; Luster: vitreous (glassy); Crystal structure: hexagonal/trigonal; Cleavage: none (conchoidal fracture); Specific gravity: 2.65

Formation & geological history

Forms in hydrothermal veins or as linings in volcanic geodes (typically basalt) when silica-rich water deposits crystals. The purple color is caused by irradiation and trivalent iron (Fe3+) impurities within the quartz lattice.

Uses & applications

Primarily used as a gemstone for jewelry, in ornamental carvings, and widely collected by mineral enthusiasts for aesthetic and metaphysical purposes.

Geological facts

Amethyst was considered one of the five cardinal gemstones until large deposits were found in Brazil in the 1700s. The name comes from the Ancient Greek word 'amethystos', meaning 'not intoxicated', as it was believed to prevent drunkenness.

Field identification & locations

Identify in the field by its purple color, quartz-like hexagonal crystal habit, and its ability to scratch glass. Found globally, with major deposits in Brazil, Uruguay, Zambia, and Ontario, Canada.