igneous
Granite (weathered, possibly porphyritic)
Granite; primarily quartz (SiO₂), feldspars, and mica/amphibole
AI-generated identification · may be incorrectCoarse-grained, pinkish-gray rock with visible interlocking crystals and dark minerals; quartz is Mohs 7, feldspar about 6, and overall hardness roughly 6–7. It has a granular texture, vitreous-to-dull luster, no strong cleavage as a rock, and typical specific gravity around 2.6–2.7.
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Physical properties
Coarse-grained, pinkish-gray rock with visible interlocking crystals and dark minerals; quartz is Mohs 7, feldspar about 6, and overall hardness roughly 6–7. It has a granular texture, vitreous-to-dull luster, no strong cleavage as a rock, and typical specific gravity around 2.6–2.7.
Formation & geological history
Formed when silica-rich magma cooled slowly deep in the crust, allowing large crystals to grow; most granite formed during Precambrian to Phanerozoic plutonic events and was later uplifted and weathered.
Uses & applications
Widely used as dimension stone, countertops, monuments, paving, aggregate, and landscaping material; attractive pink specimens may be collected but are generally low value.
Geological facts
Pink coloration commonly comes from potassium feldspar, while dark flecks are biotite or hornblende. The irregular surface and oxidation suggest weathering rather than polishing.
Field identification & locations
Identify it by its visibly interlocking quartz, feldspar, and dark mineral grains, lack of layering, and inability to scratch with a steel knife; acid will not fizz. Common worldwide in continental mountain belts and exposed plutons.
