igneous
Pink-and-gray granite or granitic gneiss
Quartz–feldspar granite; possibly foliated granitic gneiss
AI-generated identification · may be incorrectCoarse, interlocking texture with pale pink potassium feldspar, gray quartz, and dark biotite/amphibole; vitreous quartz and feldspar luster, Mohs hardness about 6–7, poor cleavage as a rock, and specific gravity roughly 2.6–2.8.
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Physical properties
Coarse, interlocking texture with pale pink potassium feldspar, gray quartz, and dark biotite/amphibole; vitreous quartz and feldspar luster, Mohs hardness about 6–7, poor cleavage as a rock, and specific gravity roughly 2.6–2.8.
Formation & geological history
Granite crystallizes slowly from silica-rich magma deep underground, generally during Precambrian to younger continental magmatism; gneissic banding indicates later high-grade metamorphism. The specimen’s weathered surface obscures whether it is true granite or gneiss.
Uses & applications
Commonly used as dimension stone, building aggregate, countertops, monuments, and landscaping stone; this rough fragment has little jewelry value.
Geological facts
Pink coloration typically comes from potassium feldspar, while dark patches are biotite or amphibole. Granite is one of Earth’s most widespread continental crustal rocks.
Field identification & locations
Identify it by visible pink feldspar, gray translucent quartz, and black mica/amphibole in a coarse crystalline matrix; weak foliation favors gneiss. Common worldwide, especially in exposed continental shields and mountain belts.
