igneous
Weathered granite cobble
Granite, a coarse-grained felsic intrusive igneous rock
AI-generated identification · may be incorrectGray-white with dark mineral flecks and a rough, rounded weathered surface; likely quartz, feldspar, and mica or amphibole. Individual grains are not clearly resolved, so hardness and texture are estimates: quartz is Mohs 7, feldspar about 6, and granite has no overall cleavage.
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Physical properties
Gray-white with dark mineral flecks and a rough, rounded weathered surface; likely quartz, feldspar, and mica or amphibole. Individual grains are not clearly resolved, so hardness and texture are estimates: quartz is Mohs 7, feldspar about 6, and granite has no overall cleavage.
Formation & geological history
Formed when silica-rich magma cooled slowly underground, allowing crystals to grow; the specimen’s age cannot be determined from the photograph. The rounded shape likely reflects transport and abrasion in water or prolonged weathering.
Uses & applications
Granite is widely used for building stone, paving, countertops, and aggregate; this cobble is mainly suitable for collecting or landscaping.
Geological facts
The mottled pattern comes from intergrown light-colored quartz and feldspar with darker minerals; granite is a rock, not a single mineral.
Field identification & locations
Look for a hard, interlocking mix of light and dark grains; quartz will scratch glass. Granite is plausible in Taiwan’s geologically varied terrain near the reported area, but the image alone cannot confirm local provenance.
