mineral
Amethyst
Quartz (Silicon Dioxide, SiO2)
Hardness of 7 on the Mohs scale, purple to violet color due to iron impurities and natural irradiation, vitreous (glassy) luster, hexagonal crystal system, conchoidal fracture with no true cleavage, specific gravity of 2.65.
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Physical properties
Hardness of 7 on the Mohs scale, purple to violet color due to iron impurities and natural irradiation, vitreous (glassy) luster, hexagonal crystal system, conchoidal fracture with no true cleavage, specific gravity of 2.65.
Formation & geological history
Forms within gas cavities (vesicles) in basaltic volcanic rocks, or as linings in hydrothermal veins, where silica-rich solutions cool and precipitate quartz crystals over millions of years.
Uses & applications
Widely used as a gemstone in jewelry, for decorative home displays, in spiritual and metaphysical practices, and occasionally in industrial applications requiring high-purity silica.
Geological facts
Amethyst was once considered one of the cardinal gemstones of high value until large deposits were discovered in Brazil. Its purple color can fade or change to yellow (citrine) when exposed to intense heat.
Field identification & locations
Easily identifiable by its distinct purple coloration and hexagonal crystal points growing inside a geode matrix. Major deposits are found in Brazil, Uruguay, Zambia, and the United States.
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