mineral

Amethyst

Amethyst (Silicon Dioxide with Iron impurities), SiO₂

Hardness: 7 on Mohs scale; Color: Pale lilac to deep royal purple; Luster: Vitreous (glass-like); Crystal structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Hardness: 7 on Mohs scale
Color: Pale lilac to deep royal purple
Luster: Vitreous (glass-like)

Identified March 30, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Pale lilac to deep royal purple; Luster: Vitreous (glass-like); Crystal structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Formation & geological history

Formed in hydrothermal veins or cavities within igneous rocks (geodes). The purple color is caused by irradiation of trivalent iron (Fe3+) impurities within the quartz lattice. Most commercial specimens are from the Cretaceous period (approx. 100-135 million years old).

Uses & applications

Primary use is in jewelry (faceted gemstones, cabochons) and as decorative specimens for collectors. It is also a popular stone in metaphysical circles and home decor (amethyst cathedrals).

Geological facts

Amethyst was considered a Cardinal Gem (one of the five most precious stones) until large deposits were found in Brazil in the 1700s. Its name comes from the Ancient Greek 'amethystos', meaning 'not intoxicated', as it was believed to prevent drunkenness.

Field identification & locations

Identify by its characteristic purple color and hexagonal prism crystal habits. It can be found globally, with major deposits in Brazil and Uruguay. For collectors, look for deep 'Siberian' purple saturation and crystal clarity without 'color zoning'.

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