igneous
Rounded granite cobble
Granite; chiefly quartz, feldspar, and mica/amphibole
AI-generated identification · may be incorrectCoarse-grained, pink-gray and speckled, with a dull to slightly glassy luster; typical hardness is 6–7 Mohs, no cleavage as a rock, and specific gravity about 2.6–2.7. The rounded shape indicates natural abrasion or tumbling.
Identified More igneous →
Explore Rounded granite cobble in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Coarse-grained, pink-gray and speckled, with a dull to slightly glassy luster; typical hardness is 6–7 Mohs, no cleavage as a rock, and specific gravity about 2.6–2.7. The rounded shape indicates natural abrasion or tumbling.
Formation & geological history
Granite crystallizes slowly from silica-rich magma deep in continental crust, commonly during Precambrian to Phanerozoic mountain-building events; this specimen was later weathered and transported as a cobble.
Uses & applications
Used extensively as crushed stone, aggregate, building stone, countertops, monuments, and landscaping material; this small rounded piece has minimal commercial value.
Geological facts
Visible interlocking grains and pink feldspar distinguish it from many volcanic rocks. Exact identification is limited by the image; it could also be a closely related granitic rock such as granodiorite.
Field identification & locations
Look for quartz’s gray translucent grains, pink/white feldspar, and dark mica or amphibole in an interlocking texture; granite is common in continental terrains worldwide. A hand lens and acid test can help separate it from carbonate rocks.
