mineral

Amethyst cluster

Quartz, purple variety; silicon dioxide (SiO₂) colored mainly by iron-related defects and irradiation

AI-generated identification · may be incorrect

Typically Mohs hardness 7, vitreous luster, hexagonal crystal structure, conchoidal fracture, and no cleavage; purple quartz crystals occur on a white-to-brown drusy or matrix coating, as shown.

Identified September 6, 2026More mineral →

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Physical properties

Typically Mohs hardness 7, vitreous luster, hexagonal crystal structure, conchoidal fracture, and no cleavage; purple quartz crystals occur on a white-to-brown drusy or matrix coating, as shown.

Formation & geological history

Forms when silica-rich hydrothermal fluids fill cavities in volcanic rocks, especially basaltic vesicles; crystals commonly grew during the Cenozoic, though ages vary by deposit.

Uses & applications

Used as a collectible mineral, ornamental specimen, and gemstone; fine transparent crystals may be faceted, while clusters are sold for display and metaphysical markets.

Geological facts

Amethyst’s purple color can fade with prolonged heat or strong sunlight and may turn yellow-orange when heated, producing citrine-like material.

Field identification & locations

Identify it by purple, glassy, six-sided quartz crystals on a cavity matrix; common sources include Brazil, Uruguay, Zambia, Namibia, and Mexico. The image most likely shows natural amethyst on host rock.