igneous
Granite
Coarse-grained felsic intrusive igneous rock; primarily quartz, alkali feldspar, plagioclase, and biotite/hornblende
AI-generated identification · may be incorrectHardness about 6–7 Mohs; light gray with black and whitish grains, granular texture, and vitreous-to-dull luster. Crystals are interlocking and show no prominent cleavage as a whole, though feldspar and mica do.
Identified More igneous →
Explore Granite in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness about 6–7 Mohs; light gray with black and whitish grains, granular texture, and vitreous-to-dull luster. Crystals are interlocking and show no prominent cleavage as a whole, though feldspar and mica do.
Formation & geological history
Forms when silica-rich magma cools slowly deep underground, producing visible crystals; most examples formed during Precambrian to Phanerozoic mountain-building events.
Uses & applications
Widely used for countertops, monuments, building stone, paving, and aggregate; attractive polished pieces are collected but usually have modest value.
Geological facts
The specimen’s visible quartz-like gray grains, pale feldspar, and dark mafic minerals are characteristic of granite, though granodiorite is also possible from a photograph.
Field identification & locations
Identify it by its coarse interlocking grains, hardness, and lack of layering or foliation; common worldwide in continental crust, especially mountain belts and ancient shields.
