mineral

Smoky quartz crystal cluster

Quartz, silicon dioxide (SiO₂), smoky variety

AI-generated identification · may be incorrect

Hardness 7 Mohs; translucent gray-brown to nearly black crystals with a vitreous luster, hexagonal/trigonal crystal structure, and indistinct cleavage. The specimen appears to include milky/clear quartz surrounding darker smoky quartz crystals.

Identified September 13, 2026More mineral →

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Physical properties

Formation & geological history

Forms in silica-rich hydrothermal veins, cavities, and granitic pegmatites; smoky color commonly results from natural irradiation affecting aluminum impurities. Crystals formed over geologic timescales, often during late-stage cooling of granitic systems.

Uses & applications

Used as a decorative and collector specimen; attractive transparent pieces may be faceted as gemstones. Quartz is also important industrially in glass, electronics, abrasives, and engineered stone.

Geological facts

Smoky quartz can range from pale champagne to opaque black (“morion”); heating may remove its color, while irradiation can intensify it.

Field identification & locations

Identify by its glassy luster, hexagonal crystal faces, lack of obvious cleavage, and ability to scratch ordinary glass. Common sources include Brazil, Switzerland, Scotland, Madagascar, the United States, and Colorado; this example may be a smoky-quartz cluster with milky quartz.