mineral

Amethyst Geode

Amethyst (Silicon Dioxide, SiO2)

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

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

Identified July 2, 2026More mineral →

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Physical properties

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

Formation & geological history

Formed in hollow cavities (geodes) within volcanic rock through hydrothermal deposition of silica-rich fluids. The purple color is caused by trace amounts of iron and natural irradiation over millions of years. Common in basaltic lava flows.

Uses & applications

Used extensively in jewelry, as decorative display pieces, for crystal healing groups, and as a popular mineral specimen for collectors.

Geological facts

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

Field identification & locations

Identify in the field by looking for vugs or nodules in volcanic rock. When cracked open, they reveal purple crystals pointing toward the center. Frequently found in Brazil, Uruguay, and Morocco.