mineral

Smoky quartz crystal

Quartz (SiO₂), naturally irradiated smoky variety

AI-generated identification · may be incorrect

Hardness 7 Mohs; translucent brown-gray to nearly black, with a vitreous luster and conchoidal fracture. Trigonal crystal structure; typically lacks cleavage, though the specimen appears partly cut or naturally terminated.

Identified August 20, 2026More mineral →

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Physical properties

Formation & geological history

Forms in hydrothermal veins, pegmatites, and cavities in igneous rocks as silica-rich fluids cool. Smoky coloration develops from irradiation acting on trace aluminum; individual crystals may be millions to hundreds of millions of years old.

Uses & applications

Used as a collectible mineral and occasionally as a gemstone; quartz is also important in glass, electronics, abrasives, and construction aggregate.

Geological facts

The image most closely matches smoky quartz, although lighting and the apparent polishing/cutting prevent definitive identification. Dark specimens are sometimes called morion.

Field identification & locations

Look for glassy luster, hardness sufficient to scratch ordinary glass, no cleavage, and six-sided prismatic crystal forms; common localities include Brazil, Switzerland, Madagascar, the United States, and Scotland.