mineral

Amethyst

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Purple, violet, or lavender; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65.

Hardness: 7 on Mohs scale
Color: Purple, violet, or lavender
Luster: Vitreous (glassy)

Identified July 13, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Purple, violet, or 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 when silica-rich water fills cavities. The purple color is caused by irradiation of iron impurities within the quartz structure.

Uses & applications

Primarily used as a semi-precious gemstone in jewelry, for decorative home decor (geodes and clusters), and by mineral collectors.

Geological facts

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

Field identification & locations

Identify by its characteristic purple color and hexagonal crystal points. Often found in Brazil, Uruguay, Zambia, and South Korea. Look for hexagonal cross-sections and lack of cleavage.