Rock Identifier
Amethyst cluster (Quartz, SiO₂, violet variety (amethyst)) — mineral
mineral

Amethyst cluster

Quartz, SiO₂, violet variety (amethyst)

AI-generated identification · may be incorrect

Hardness 7 Mohs; pale violet to purple, vitreous luster, hexagonal crystal structure, and no true cleavage (conchoidal fracture). The specimen appears to be a small natural crystal cluster, possibly with a druzy coating.

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Physical properties

Hardness 7 Mohs; pale violet to purple, vitreous luster, hexagonal crystal structure, and no true cleavage (conchoidal fracture). The specimen appears to be a small natural crystal cluster, possibly with a druzy coating.

Formation & geological history

Forms when iron-bearing quartz crystallizes in gas cavities and fractures of volcanic rocks, especially basalt; purple color develops through irradiation and heating. Most gem amethyst is Cenozoic to Mesozoic in age, though exact age requires provenance.

Uses & applications

Used for ornamental specimens, jewelry, carvings, and metaphysical collecting; small clusters have modest decorative value.

Geological facts

Amethyst’s purple color can fade with prolonged sunlight or heating. Its name derives from the Greek amethystos, meaning “not intoxicated.”

Field identification & locations

Identify by glassy luster, six-sided crystal faces, quartz hardness, and violet color; common sources include Brazil, Uruguay, Zambia, and Mexico. A field test should avoid scratching valuable crystals; quartz will scratch glass and resist a steel knife.