igneous
Black-and-copper polished granite
Biotite granite, likely a commercial gabbro/granite variety
AI-generated identification · may be incorrectCoarse-grained, interlocking crystals with black biotite or hornblende, gray feldspar/quartz, and pink-orange potassium feldspar; vitreous to dull luster, Mohs hardness about 6–7, no obvious cleavage as a whole rock, specific gravity roughly 2.6–2.8.
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Physical properties
Coarse-grained, interlocking crystals with black biotite or hornblende, gray feldspar/quartz, and pink-orange potassium feldspar; vitreous to dull luster, Mohs hardness about 6–7, no obvious cleavage as a whole rock, specific gravity roughly 2.6–2.8.
Formation & geological history
A plutonic igneous rock formed when silica-rich magma cooled slowly deep underground, allowing large crystals to develop; typically Precambrian to Phanerozoic in age depending on quarry source.
Uses & applications
Commonly used for countertops, tiles, monuments, flooring, and polished architectural stone; usually low collector value.
Geological facts
The orange-pink areas are potassium feldspar, while dark minerals are probably biotite and/or hornblende. The glossy surface appears polished, and the small pale object may be unrelated debris.
Field identification & locations
Identify it by its visible interlocking crystals, speckled pattern, and resistance to scratching; it is not equivalent to a single mineral crystal. Similar commercial stones are quarried worldwide, especially in India, Brazil, China, Scandinavia, and southern Africa.
