mineral

Smoky quartz

Quartz (SiO₂), naturally irradiated brown variety

AI-generated identification · may be incorrect

Mohs hardness 7; translucent smoky-brown color, vitreous luster, conchoidal fracture, no cleavage, hexagonal crystal structure, and specific gravity about 2.65. The rough fracture and color are consistent with quartz, though photographic identification is not definitive.

Identified August 11, 2026More mineral →

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Physical properties

Formation & geological history

Forms in silica-rich hydrothermal veins, pegmatites, and cavities in igneous rocks; coloration develops from irradiation of aluminum-bearing quartz over geological time, commonly in Precambrian to younger rocks.

Uses & applications

Used as a collectible mineral, ornamental stone, and occasionally in jewelry; clear, well-formed crystals are most valued.

Geological facts

Smoky quartz can fade with prolonged heating or strong sunlight, while very dark material may resemble morion. It commonly occurs with feldspar, mica, and other quartz varieties.

Field identification & locations

Common localities include Brazil, Switzerland, Scotland, the United States, and Madagascar. Check for glass-like luster, hardness sufficient to scratch ordinary glass, conchoidal fracture, and lack of bubbles; iron staining may produce the rusty band visible here.