igneous
Polished granite pebble
Granite, a coarse-grained felsic intrusive igneous rock, typically composed of quartz, potassium feldspar, plagioclase, and biotite or other dark minerals
AI-generated identification · may be incorrectVisible interlocking white, gray, and black grains with a polished luster. Individual mineral hardnesses are about 2–7 on the Mohs scale; granite has no consistent cleavage and typically has a specific gravity near 2.6–2.7.
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Physical properties
Visible interlocking white, gray, and black grains with a polished luster. Individual mineral hardnesses are about 2–7 on the Mohs scale; granite has no consistent cleavage and typically has a specific gravity near 2.6–2.7.
Formation & geological history
Granite forms when silica-rich magma cools slowly underground, allowing visible crystals to grow. Such rocks occur in ancient continental crust across a wide range of geological ages.
Uses & applications
Used in buildings, countertops, paving, monuments, and decorative stone; small polished pebbles are also sold as collectibles or craft materials.
Geological facts
The image shows a small, rounded, polished specimen with the speckled texture characteristic of granite, though a photo cannot confirm its exact mineral proportions.
Field identification & locations
Identify it by its coarse, interlocking light and dark grains rather than layers or fossils. Granite is widespread worldwide; the pebble’s source cannot be determined from appearance alone.
