igneous
Weathered granite or granitic gneiss
Granite; chiefly quartz, feldspar, and mica
AI-generated identification · may be incorrectCoarse-grained, speckled white, tan, and gray rock with a granular texture; likely Mohs 6–7, vitreous quartz/feldspar luster, no obvious cleavage as a whole, and specific gravity around 2.6–2.7.
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Physical properties
Coarse-grained, speckled white, tan, and gray rock with a granular texture; likely Mohs 6–7, vitreous quartz/feldspar luster, no obvious cleavage as a whole, and specific gravity around 2.6–2.7.
Formation & geological history
Crystallized slowly from silica-rich magma deep underground, commonly during Precambrian to Phanerozoic mountain-building events; surface weathering rounded and exposed the specimen’s grains.
Uses & applications
Used extensively as building stone, countertops, monuments, aggregate, and landscaping rock; attractive pieces may be collected but this specimen appears common and unpolished.
Geological facts
The pale grains are probably feldspar and quartz, while darker flecks may be biotite or hornblende. If foliation or compositional banding is present, the specimen may instead be granitic gneiss.
Field identification & locations
Identify with visible interlocking crystals, hardness, and a scratch test: quartz and feldspar resist a steel knife, while calcite-rich rocks fizz in acid. Common worldwide, especially in exposed continental shields and mountain ranges.
