Rock Identifier
Smoky quartz crystal (probable) (Quartz, silicon dioxide (SiO₂), likely iron-colored smoky quartz) — mineral
mineral

Smoky quartz crystal (probable)

Quartz, silicon dioxide (SiO₂), likely iron-colored smoky quartz

AI-generated identification · may be incorrect

Translucent gray-brown fragment with a vitreous luster and conchoidal-looking fracture; quartz hardness is 7 Mohs, lacks cleavage, and has hexagonal crystal structure. The apparent metallic/dark coating may be matrix, iron staining, or surface alteration.

Identified More mineral
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Physical properties

Translucent gray-brown fragment with a vitreous luster and conchoidal-looking fracture; quartz hardness is 7 Mohs, lacks cleavage, and has hexagonal crystal structure. The apparent metallic/dark coating may be matrix, iron staining, or surface alteration.

Formation & geological history

Forms in silica-rich hydrothermal veins, pegmatites, and cavities in igneous rocks; coloration commonly results from natural irradiation affecting aluminum impurities. The specimen’s exact age and locality cannot be determined from the image.

Uses & applications

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

Geological facts

Smoky quartz ranges from pale champagne to nearly black “morion.” A glass fragment can look similar, but quartz is harder and typically shows natural crystal faces or distinctive conchoidal fracture.

Field identification & locations

Common localities include Brazil, Switzerland, Madagascar, the United States, and Scotland. Confirm with a hardness test, crystal-face inspection, and specific-gravity measurement; avoid scratching valuable specimens.