mineral

Amethyst-bearing quartz geode or crystal cluster

Quartz, SiO₂; purple coloration from trace iron and irradiation

AI-generated identification · may be incorrect

Likely quartz with violet, drusy-to-coarse crystal faces and a vitreous luster; Mohs hardness 7, no cleavage, conchoidal fracture, and specific gravity about 2.65. The dark appearance may result from inclusions, matrix, or low lighting.

Identified September 22, 2026More mineral →

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Physical properties

Formation & geological history

Amethyst forms when silica-rich hydrothermal fluids or gas cavities in volcanic rocks deposit quartz, with iron producing purple color. Most specimens formed in volcanic cavities during the Cenozoic or older basaltic episodes, depending on locality.

Uses & applications

Used as a decorative and collection specimen, and occasionally in jewelry when transparent enough to cut. Common material has modest commercial value.

Geological facts

Amethyst is the purple variety of quartz; color can fade with prolonged strong heat or sunlight. The image does not clearly show enough crystal habit or matrix to determine a precise locality.

Field identification & locations

Common sources include Brazil, Uruguay, Zambia, Namibia, and Mexico. Identify it by purple color, glassy luster, hardness sufficient to scratch ordinary glass, and six-sided quartz crystals; confirm with a streak and hardness test only on an inconspicuous area.