mineral

Smoky quartz-bearing pegmatitic rock

Quartz, SiO₂, likely with feldspar and mica inclusions

AI-generated identification · may be incorrect

Translucent gray-brown to smoky color, vitreous-to-greasy luster, irregular massive crystals and no obvious cleavage; quartz hardness is Mohs 7, with specific gravity about 2.65. The rough, intergrown texture suggests a quartz-rich pegmatite rather than a single crystal.

Identified August 9, 2026More mineral →

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Physical properties

Formation & geological history

Formed when silica-rich magma cooled slowly in a pegmatite, allowing coarse quartz and associated minerals to crystallize; commonly Precambrian to Phanerozoic in age. The smoky color may result from irradiation and trace aluminum impurities.

Uses & applications

Used as a collectible mineral specimen; clear portions may be cut as smoky-quartz gemstones. Quartz is also important in glassmaking, electronics, abrasives, and engineered stone.

Geological facts

Quartz commonly shows conchoidal fracture and can scratch ordinary glass. The specimen appears partly weathered and matrix-rich, so exact identification of the dark inclusions requires testing or magnification.

Field identification & locations

Common in granitic pegmatites and hydrothermal veins worldwide, especially Brazil, Madagascar, the United States, and Switzerland. Confirm with a glass-scratch test, lack of cleavage, and ideally hardness, streak, and microscopy; feldspar or mica may form the surrounding matrix.