mineral
Amethyst (Tumbled)
Quartz (SiO2) with iron impurities
AI-generated identification · may be incorrectHardness: 7 (Mohs), Color: pale purple to deep violet, Luster: Vitreous (glassy) when polished, Crystal structure: Trigonal (often seen in raw form, obscured here by tumbling), Cleavage: None (conchoidal fracture)
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Physical properties
Hardness: 7 (Mohs), Color: pale purple to deep violet, Luster: Vitreous (glassy) when polished, Crystal structure: Trigonal (often seen in raw form, obscured here by tumbling), Cleavage: None (conchoidal fracture)
Formation & geological history
Forms in geodes or vugs in volcanic rocks, as well as in hydrothermal veins. The purple color is due to irradiation of iron impurities.
Uses & applications
Commonly used in jewelry, decorative arts, crystal healing practices, and as collector specimens.
Geological facts
Amethyst is the birthstone for February. It was historically considered as valuable as ruby or emerald until large deposits were found in Brazil.
Field identification & locations
Identified by its distinctive purple color and quartz hardness (can scratch glass). Commonly found in Brazil, Uruguay, and Zambia.
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