igneous
Weathered granite-like rock
Granite, likely biotite-bearing; exact identification is uncertain from the image
AI-generated identification · may be incorrectCoarse, irregular granular texture with pale gray feldspar/quartz and dark biotite or other mafic minerals; typically Mohs 6–7, vitreous to dull luster, no strong cleavage as a whole, and specific gravity about 2.6–2.8.
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Physical properties
Coarse, irregular granular texture with pale gray feldspar/quartz and dark biotite or other mafic minerals; typically Mohs 6–7, vitreous to dull luster, no strong cleavage as a whole, and specific gravity about 2.6–2.8.
Formation & geological history
Formed by slow cooling and crystallization of silica-rich magma deep in the crust, commonly during Precambrian to Phanerozoic mountain-building events; surface weathering has roughened and darkened this fragment.
Uses & applications
Used extensively as building stone, countertops, monuments, aggregate, and paving; small natural pieces have minimal commercial value unless unusually attractive or provenance-rich.
Geological facts
Granite is an aggregate of interlocking minerals rather than a single mineral, and its visible crystals indicate intrusive cooling. The specimen may alternatively be a weathered granitic gneiss or similar felsic rock.
Field identification & locations
Look for visible interlocking quartz, feldspar, and dark mica; a glassy quartz grain and hardness sufficient to scratch ordinary glass support identification. Common worldwide, especially in continental shields and mountain belts.
