igneous
Polished granite
Granite; chiefly quartz, feldspar, and mica/amphibole
AI-generated identification · may be incorrectCoarse-grained, interlocking crystalline texture with cream to salmon-pink feldspar, translucent gray quartz, and black biotite or hornblende. Mohs hardness is about 6–7; vitreous quartz and pearly feldspar luster, no consistent cleavage as a whole, and specific gravity around 2.63–2.75.
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Physical properties
Coarse-grained, interlocking crystalline texture with cream to salmon-pink feldspar, translucent gray quartz, and black biotite or hornblende. Mohs hardness is about 6–7; vitreous quartz and pearly feldspar luster, no consistent cleavage as a whole, and specific gravity around 2.63–2.75.
Formation & geological history
An intrusive igneous rock formed by slow cooling of silica-rich magma deep in the continental crust, commonly during Precambrian to Phanerozoic mountain-building events. The rounded, glossy surface indicates later tumbling or polishing.
Uses & applications
Used extensively for countertops, monuments, tiles, aggregate, and dimension stone; polished pieces are sold as decorative or educational specimens. This small tumbled specimen generally has modest collector value.
Geological facts
The dark material is likely biotite mica or hornblende, while the salmon areas are potassium feldspar and the pale translucent areas are quartz. Its granular texture distinguishes it from similarly colored marble.
Field identification & locations
Identify it by visible interlocking grains and the mixture of quartz, feldspar, and dark minerals; granite commonly occurs in continental plutons and exposed mountain ranges worldwide. A hardness test, streak test, and close inspection with a loupe can confirm the minerals.
