mineral

Amethyst Geode

Silicon Dioxide (SiO2) with iron impurities

Hardness: 7 on Mohs scale; Color: Pale lavender to deep violet; Luster: Vitreous (glassy); Crystal Structure: Hexagonal/Trigonal; Cleavage: None/Conchoidal fracture; Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: Pale lavender to deep violet
Luster: Vitreous (glassy)

Identified May 10, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Pale lavender to deep violet; Luster: Vitreous (glassy); Crystal Structure: Hexagonal/Trigonal; Cleavage: None/Conchoidal fracture; Specific Gravity: 2.65

Formation & geological history

Formed in gas cavities (vesicles) within volcanic rocks or sedimentary geodes where silica-rich fluids permeate and slowly crystallize over millions of years, often in the Cenozoic era.

Uses & applications

Primarily used in jewelry, as decorative collector specimens, and in spiritual/healing practices. Large crystal beds are also used for high-end interior design.

Geological facts

The purple color comes from irradiation, iron impurities, and the presence of trace elements. It was once considered as precious as diamonds until large deposits were found in Brazil.

Field identification & locations

Identify by its distinctive purple crystal points and typical white/gray chalcedony shell (rind). Commonly found in Brazil, Uruguay, and Namibia. Collectors look for deep saturation and clarity.

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