mineral

Amethyst-bearing quartz

Quartz, SiO₂, with purple amethyst zoning and likely white milky quartz

AI-generated identification · may be incorrect

Mohs hardness 7; translucent to opaque, glassy to waxy luster, purple-and-white coloration, and conchoidal fracture. Quartz is trigonal (hexagonal family) and lacks cleavage; the specimen appears massive and uncrystallized.

Identified September 13, 2026More mineral →

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Physical properties

Formation & geological history

Forms when silica-rich hydrothermal fluids or volcanic cavities deposit quartz, with trace iron producing amethyst’s purple color. The image cannot establish a precise age; deposits commonly formed in volcanic rocks during the Cenozoic or older hydrothermal events.

Uses & applications

Used as a decorative and lapidary stone, in carvings, cabochons, and jewelry; quartz is also important industrially in glass, electronics, and abrasives. This rough, low-grade piece is primarily a collector specimen.

Geological facts

Purple color generally reflects irradiation plus iron impurities, often modified by heating. Uneven purple zoning and white quartz are typical of amethyst-bearing geodes and veins.

Field identification & locations

Identify by hardness, glassy luster, conchoidal fracture, and purple quartz zones; it should scratch glass but not be scratched by a steel knife. Common sources include Brazil, Uruguay, Zambia, Bolivia, and Mexico.