igneous
Granite
Granite, a coarse-grained felsic intrusive igneous rock composed mainly of quartz, feldspar, and mica
AI-generated identification · may be incorrectGray, speckled, and visibly crystalline with a granular texture; typical hardness is about 6–7 Mohs. Minerals have a vitreous to pearly luster; cleavage occurs within individual feldspar and mica grains, not across the rock.
Identified More igneous →
Explore Granite in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Gray, speckled, and visibly crystalline with a granular texture; typical hardness is about 6–7 Mohs. Minerals have a vitreous to pearly luster; cleavage occurs within individual feldspar and mica grains, not across the rock.
Formation & geological history
Forms when silica-rich magma cools slowly underground, allowing large crystals to grow. Granite occurs in ancient continental crust, with ages ranging from hundreds of millions to billions of years.
Uses & applications
Used as building and monument stone, countertops, paving, and decorative aggregate; smaller pieces are common educational and collecting specimens.
Geological facts
Its light and dark speckles reflect intergrown mineral grains, usually quartz and feldspar with darker biotite or amphibole.
Field identification & locations
Identify by its interlocking visible crystals and lack of layering; confirm quartz by its glassy appearance and lack of cleavage. Found widely in continental mountain belts and exposed shields; the pictured rock appears granite-like, though a photo cannot confirm its identity.
