igneous
Rounded granite pebble
Granite; chiefly quartz, feldspar, and mica
AI-generated identification · may be incorrectLight gray to tan, fine- to medium-grained, speckled black and cream; typically Mohs 6–7, with a granular texture, vitreous quartz/feldspar luster, and no obvious cleavage on the rounded surface. Specific gravity is about 2.63–2.75.
Identified More igneous →
Explore Rounded granite pebble in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Light gray to tan, fine- to medium-grained, speckled black and cream; typically Mohs 6–7, with a granular texture, vitreous quartz/feldspar luster, and no obvious cleavage on the rounded surface. Specific gravity is about 2.63–2.75.
Formation & geological history
An intrusive igneous rock crystallized slowly from silica-rich magma, commonly during Precambrian to Phanerozoic mountain-building events; its rounded shape indicates later stream, beach, or glacial abrasion.
Uses & applications
Used extensively as dimension stone, countertops, paving, monuments, aggregate, and landscaping material; attractive polished pieces are also collected as curios or paperweights.
Geological facts
The visible dark grains are likely biotite or amphibole, while pale grains are feldspar and quartz. Exact identification requires a fresh surface or magnification because weathering can obscure grain boundaries.
Field identification & locations
Common worldwide, especially in continental shields and mountain belts; look for interlocking grains, abundant pale feldspar, translucent gray quartz, and scattered dark mica. A hand lens and streak/acid tests help distinguish it from similar gneiss or quartzite.
