igneous
Rounded granite cobble
Granite, a coarse-grained felsic intrusive igneous rock
AI-generated identification · may be incorrectGray to tan, granular and speckled, with a dull weathered surface; typically quartz, feldspar, and mica. Mohs hardness about 6–7; crystals are interlocking, with no prominent cleavage as a whole rock.
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Physical properties
Gray to tan, granular and speckled, with a dull weathered surface; typically quartz, feldspar, and mica. Mohs hardness about 6–7; crystals are interlocking, with no prominent cleavage as a whole rock.
Formation & geological history
Magma cooled slowly underground, likely millions to billions of years ago; later weathering and transport rounded the cobble. The image does not allow precise age or source identification.
Uses & applications
Granite is widely used for building stone, paving, countertops, and landscaping; this cobble is most suitable for decorative or educational use.
Geological facts
Granite’s visible grains formed as minerals crystallized together during slow cooling. Its rounded shape indicates prolonged abrasion or water transport.
Field identification & locations
Look for a hard, speckled rock with interlocking light quartz/feldspar grains and darker mica; common in river and glacial deposits worldwide. Image-based identification is approximate.
