mineral

Smoky quartz crystal cluster

Quartz, silicon dioxide (SiO₂), likely smoky quartz with milky quartz matrix

AI-generated identification · may be incorrect

Typically Mohs hardness 7, vitreous luster, hexagonal crystal structure, and no cleavage; the dark translucent color is smoky brown to nearly black, while the matrix is white-gray and granular. The visible pointed, striated crystal faces are characteristic of quartz.

Identified August 15, 2026More mineral →

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Physical properties

Formation & geological history

Forms in hydrothermal veins, pegmatites, and cavities in igneous rocks when silica-rich fluids crystallize; smoky coloration commonly results from natural irradiation affecting trace aluminum. Exact age and locality cannot be determined from the image.

Uses & applications

Used as a collector specimen and occasionally in jewelry; quartz is also important industrially in glass, ceramics, electronics, abrasives, and engineered stone.

Geological facts

Quartz crystals commonly show six-sided prisms ending in pyramidal points, though this specimen appears partly broken or attached to a rough matrix.

Field identification & locations

Common localities include Brazil, Switzerland, Madagascar, the United States, and Namibia. Confirm with a glass-scratch test, strong vitreous luster, and lack of cleavage; visual identification is approximate because dark glass or slag can resemble it.