mineral

Amethyst

Silicon Dioxide (SiO2) with iron impurities

Hardness: 7 (Mohs scale); Color: Pale lilac to deep purple; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65.

Hardness: 7 (Mohs scale)
Color: Pale lilac to deep purple
Luster: Vitreous (glassy)

Identified March 23, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale); Color: Pale lilac to deep purple; 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 within volcanic rock gas cavities (geodes). The purple color is caused by natural irradiation of trace iron impurities replacing silicon in the quartz lattice.

Uses & applications

Primary use is in jewelry as a gemstone and as decorative specimens for collectors or home decor. Historically used as a material for carvings and bowls.

Geological facts

The name comes from the Ancient Greek 'amethystos', meaning 'not intoxicated', as it was believed to prevent drunkenness. It is the birthstone for February.

Field identification & locations

Identify by its purple hue and typical quartz-like glassy luster and triangular crystal faces. Commonly found in Brazil, Uruguay, and Africa. To identify, check hardness (should scratch glass) and look for purple color zoning.

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