mineral

Smoky quartz fragment

Quartz, silicon dioxide (SiO₂), smoky variety

AI-generated identification · may be incorrect

Hardness 7 Mohs; translucent gray-brown color, vitreous luster, conchoidal fracture, and no prominent cleavage. The apparent triangular shape is a broken crystal fragment rather than a complete crystal.

Identified August 11, 2026More mineral →

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Physical properties

Formation & geological history

Forms when natural irradiation or trace aluminum defects darken quartz in igneous pegmatites, hydrothermal veins, and metamorphic rocks; ages vary from thousands to billions of years. The exact locality and age cannot be determined from the photograph.

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

Smoky quartz can fade with prolonged heating or intense light, while darker “morion” is the nearly opaque variety. The specimen may also be a gray-brown glassy silicate fragment, so testing is advisable.

Field identification & locations

Identify by glassy luster, conchoidal fracture, translucency, and inability to scratch it with steel; it should scratch ordinary glass but not be scratched by a steel nail. Common sources include Brazil, Madagascar, Switzerland, and the United States.