igneous
Polished pink granite cobble
Granite, chiefly potassium feldspar, plagioclase, quartz, and biotite/hornblende
AI-generated identification · may be incorrectCoarse-grained, pink-and-gray rock with black mica or amphibole; vitreous quartz, feldspar cleavage, and mottled texture. Mohs hardness is about 6–7; density typically 2.6–2.7 g/cm³; the rounded surface is naturally worn or tumbled.
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Physical properties
Coarse-grained, pink-and-gray rock with black mica or amphibole; vitreous quartz, feldspar cleavage, and mottled texture. Mohs hardness is about 6–7; density typically 2.6–2.7 g/cm³; the rounded surface is naturally worn or tumbled.
Formation & geological history
An intrusive felsic igneous rock formed by slow cooling of silica-rich magma deep in Earth’s crust, commonly during Precambrian to Mesozoic plutonic events. The cobble was later weathered and rounded by transport.
Uses & applications
Used as dimension stone, countertops, monuments, aggregate, landscaping stone, and decorative polished material; this specimen is mainly suitable for collecting or display.
Geological facts
The pink color generally comes from potassium feldspar, while dark flecks are biotite or hornblende. Visible interlocking crystals distinguish granite from many pink, fine-grained volcanic rocks.
Field identification & locations
Identify it by its coarse interlocking crystals, pink feldspar, translucent gray quartz, and scattered black minerals; it is commonly found in glacial deposits, river gravels, and granite outcrops worldwide. Exact classification may overlap with granodiorite without a thin section.
