mineral

Smoky quartz (likely included or matrix-bearing)

Quartz, silicon dioxide (SiO₂), often colored by irradiation-related defects

AI-generated identification · may be incorrect

Hardness 7 Mohs; translucent gray-brown to smoky black, with a vitreous luster and conchoidal fracture. The irregular specimen appears massive or poorly crystalline, possibly containing dark mineral inclusions; cleavage is absent, and specific gravity is about 2.65.

Identified August 20, 2026More mineral →

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Physical properties

Formation & geological history

Forms mainly in cavities of granitic pegmatites, hydrothermal veins, and metamorphic rocks as silica-rich fluids cool; smoky coloration develops from natural radiation acting on aluminum-related defects. Crystals may range from Precambrian to modern geologic ages.

Uses & applications

Used as a collectible mineral, ornamental stone, and occasionally in jewelry; clear, well-formed crystals are more valuable than opaque fragments.

Geological facts

Smoky quartz is the brown-to-black variety of quartz; very dark material is sometimes called morion. It can fade with strong heating or sunlight depending on the specimen.

Field identification & locations

Identify by its glassy luster, lack of cleavage, conchoidal fracture, and ability to scratch glass; a hardness test and inspection for quartz crystal faces would help confirm it. Common localities include Brazil, Switzerland, the United States, Madagascar, and Scotland.