igneous
Likely gray granite or gneiss fragment
Granite: quartz, feldspar, and mica; possibly banded gneiss if foliation is present
AI-generated identification · may be incorrectSmall, angular gray specimen with a granular texture and subtle light-dark mineral flecks. Typical granite hardness is about 6–7 Mohs, nonmetallic luster, interlocking crystals, and no obvious cleavage as a whole rock.
Identified More igneous →
Explore Likely gray granite or gneiss fragment in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Small, angular gray specimen with a granular texture and subtle light-dark mineral flecks. Typical granite hardness is about 6–7 Mohs, nonmetallic luster, interlocking crystals, and no obvious cleavage as a whole rock.
Formation & geological history
Granite crystallizes slowly from silica-rich magma deep underground; gneiss forms when granite or similar rock is metamorphosed under high heat and pressure. Exact age and origin cannot be determined from the photograph.
Uses & applications
Commonly used as crushed stone, building stone, countertops, monuments, and aggregate; this small fragment has negligible commercial value.
Geological facts
The visible grain suggests multiple minerals rather than a single crystal. A fresh broken surface is more diagnostic than the weathered exterior.
Field identification & locations
Look for visible quartz, white or pink feldspar, and black mica; gneiss commonly shows distinct mineral banding. Common worldwide, especially in old continental crust and glacial deposits.
