igneous
Weathered granite or granitic gneiss
Granite; predominantly quartz, feldspar, and mica (exact identification is uncertain from the image)
AI-generated identification · may be incorrectCoarse-grained, mottled gray-brown rock with pale feldspar/quartz and dark mica or amphibole; typically Mohs 6–7, vitreous to dull luster, interlocking crystals, and no prominent cleavage as a whole rock.
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Physical properties
Coarse-grained, mottled gray-brown rock with pale feldspar/quartz and dark mica or amphibole; typically Mohs 6–7, vitreous to dull luster, interlocking crystals, and no prominent cleavage as a whole rock.
Formation & geological history
Formed by slow cooling of silica-rich magma deep underground, generally during Precambrian to Phanerozoic crustal formation; surface weathering has produced the brown coloration and rough texture.
Uses & applications
Widely used as building stone, countertops, monuments, paving, aggregate, and landscape rock; ordinary pieces have little jewelry value.
Geological facts
Granite is identified by visible interlocking crystals rather than layers; gneiss would show distinct compositional banding, which is not clearly resolved here.
Field identification & locations
Common worldwide, including continental shields and mountain belts. Look for quartz’s glassy gray appearance, pink/white feldspar, and black mica; a close, well-lit image or fresh broken surface is needed for certainty.
