mineral

Amethyst Cluster

Silicon Dioxide (Quartz variety: Amethyst), SiO2

Hardness: 7 on the Mohs scale. Color: Light to dark purple, violet, or pale lilac. Luster: Vitreous (glassy). Crystal structure: Trigonal, commonly forming prismatic crystals ending in six-sided pyramids. Cleavage: None, exhibits conchoidal fracture. Specific gravity: 2.65.

Hardness: 7 on the Mohs scale
Color: Light to dark purple, violet, or pale lilac
Luster: Vitreous (glassy)

Identified August 6, 2026More mineral →

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Physical properties

Formation & geological history

Forms in hydrothermal veins and gas cavities (vesicles) within volcanic rocks, such as basalt, where silica-rich solutions precipitate quartz crystals containing trace amounts of iron and subjected to natural irradiation over geological time.

Uses & applications

Widely used as a gemstone in jewelry, decorative items, healing crystals, and mineral collector specimens.

Geological facts

Amethyst was once considered one of the cardinal gemstones of high value alongside diamond, ruby, emerald, and sapphire until large deposits were discovered in Brazil. Its purple color is caused by irradiation of trivalent iron (Fe3+) impurities within the quartz crystal lattice.

Field identification & locations

Identified by its distinctive purple or violet color, hexagonal crystal form, and a hardness of 7 which easily scratches glass. Common sources include Brazil, Uruguay, Madagascar, and the United States (such as Arizona and Colorado).

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