igneous
Weathered granite
Granite, a coarse-grained felsic intrusive igneous rock composed mainly of quartz, feldspar, and mica
AI-generated identification · may be incorrectGray, speckled surface with light feldspar/quartz grains and darker minerals; typically Mohs 6–7, vitreous quartz luster, interlocking crystals, and no cleavage as a whole rock. The image shows an exposed, fractured outcrop; individual grains are not clear enough for precise identification.
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Physical properties
Gray, speckled surface with light feldspar/quartz grains and darker minerals; typically Mohs 6–7, vitreous quartz luster, interlocking crystals, and no cleavage as a whole rock. The image shows an exposed, fractured outcrop; individual grains are not clear enough for precise identification.
Formation & geological history
Forms when silica-rich magma cools slowly underground, commonly within continental crust; such outcrops can be hundreds of millions to billions of years old, though this specimen’s age cannot be determined from the image.
Uses & applications
Granite is used for building stone, paving, countertops, monuments, and aggregate; this outcrop has no evident specimen or jewelry value.
Geological facts
Granite commonly contains quartz, potassium feldspar, plagioclase, and biotite or hornblende. Weathering and jointing can break it into blocks and expose contrasting mineral grains.
Field identification & locations
Likely granite based on its coarse, gray, speckled appearance and massive outcrop form; confirm by examining fresh surfaces for interlocking quartz and feldspar grains. Granite is widespread in continental mountain belts and ancient shields.
