igneous
Red granite
Biotite–hornblende granite, commonly granitic plutonic rock
AI-generated identification · may be incorrectCoarse-grained, pink-red and black speckled, with interlocking quartz, feldspar, and dark mica/amphibole; quartz hardness 7, feldspar about 6, nonfoliated, generally massive, with vitreous to dull granular luster.
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Physical properties
Coarse-grained, pink-red and black speckled, with interlocking quartz, feldspar, and dark mica/amphibole; quartz hardness 7, feldspar about 6, nonfoliated, generally massive, with vitreous to dull granular luster.
Formation & geological history
Slow cooling of silica-rich magma deep within continental crust, producing a Phanerozoic or Precambrian pluton; the pictured surface is polished and likely architectural stone.
Uses & applications
Widely used for countertops, monuments, paving, cladding, gravestones, and aggregate; valued for durability and decorative color.
Geological facts
The red color is mainly from potassium feldspar, while black grains are commonly biotite and/or hornblende. Granite typically contains roughly 20–60% quartz and abundant feldspar.
Field identification & locations
Identify it by visible interlocking crystals, pink feldspar, gray-clear quartz, and black minerals; it lacks layering or foliation. Common sources include India, Brazil, Finland, China, and the United States.
