igneous
Weathered granite
Granite; chiefly quartz (SiO₂), feldspar, and mica
AI-generated identification · may be incorrectCoarse-grained, speckled white-gray rock with translucent quartz, pale feldspar, and dark mica/iron staining; typically Mohs 6–7, vitreous to dull luster, interlocking crystals, and no cleavage as a whole.
Identified More igneous →
Explore Weathered granite in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Coarse-grained, speckled white-gray rock with translucent quartz, pale feldspar, and dark mica/iron staining; typically Mohs 6–7, vitreous to dull luster, interlocking crystals, and no cleavage as a whole.
Formation & geological history
An intrusive igneous rock formed by slow cooling of silica-rich magma deep in Earth’s crust, commonly during Precambrian to Phanerozoic mountain-building events; surface weathering produced the brown staining and rough texture.
Uses & applications
Widely used as building stone, countertops, monuments, aggregate, and paving; this small weathered fragment has little commercial value but may be a useful teaching specimen.
Geological facts
Granite’s visible crystals indicate slow underground cooling. Its exact variety cannot be determined confidently from a photograph alone, and the dark grains may be biotite or hornblende.
Field identification & locations
Identify it by its granular texture and mixture of light quartz/feldspar with dark mica or amphibole; common in continental crust, mountain belts, and glacial deposits worldwide. A knife generally will not scratch quartz grains, while glass may be scratched.
