igneous
Granite
Coarse-grained felsic plutonic rock, chiefly quartz, potassium feldspar, plagioclase, and biotite/hornblende
AI-generated identification · may be incorrectTypically Mohs 6–7; pink, white, gray, and black granular appearance; vitreous quartz and feldspar luster; interlocking crystals with no cleavage as a whole, though constituent minerals may cleave. The rounded surface is naturally weathered or water-worn.
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Physical properties
Typically Mohs 6–7; pink, white, gray, and black granular appearance; vitreous quartz and feldspar luster; interlocking crystals with no cleavage as a whole, though constituent minerals may cleave. The rounded surface is naturally weathered or water-worn.
Formation & geological history
Formed by slow cooling and crystallization of silica-rich magma deep in continental crust, commonly during Precambrian to Phanerozoic plutonic events. Exact age cannot be determined from the photograph.
Uses & applications
Widely used as building stone, countertops, monuments, paving, and aggregate; attractive polished pieces are collected but usually have modest value.
Geological facts
The pink color mainly reflects potassium feldspar, while black flakes or grains are commonly biotite or amphibole. Granite’s visible interlocking crystals distinguish it from fine-grained volcanic rhyolite.
Field identification & locations
Identify it by its coarse, speckled texture, hard surface, and mixed pink/white/gray/black minerals; it does not fizz with dilute acid. Common worldwide in continental mountain belts and exposed plutons.
