igneous
Granite fragment
Granite, chiefly quartz, feldspar, and mica
AI-generated identification · may be incorrectHardness about 6–7 Mohs; coarse-grained, speckled white/gray and black, with a vitreous quartz luster and blocky feldspar cleavage. Interlocking crystals are visible, though the small specimen is somewhat blurry.
Identified More igneous →
Explore Granite fragment in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness about 6–7 Mohs; coarse-grained, speckled white/gray and black, with a vitreous quartz luster and blocky feldspar cleavage. Interlocking crystals are visible, though the small specimen is somewhat blurry.
Formation & geological history
An intrusive igneous rock crystallized slowly from silica-rich magma deep in Earth’s crust, commonly during Precambrian to Phanerozoic continental formation. Exact age cannot be determined from the photograph.
Uses & applications
Widely used as building stone, countertops, monuments, aggregate, and landscaping material; small pieces have minimal collector value.
Geological facts
The dark grains are likely biotite or hornblende, while white grains are feldspar and translucent grains may be quartz. It may alternatively be a closely related granitic rock such as granodiorite.
Field identification & locations
Identify it by its coarse, interlocking white, gray, and black grains and lack of layering or foliation; common worldwide, especially in continental mountain belts. A hardness or acid test can help distinguish it from softer limestone.
