igneous
Weathered rounded pebble
Likely altered granite or granitic gneiss fragment; exact identification is uncertain from the image
AI-generated identification · may be incorrectFine- to medium-grained, tan-brown, dull to weakly earthy luster, with diffuse pale and darker mineral patches; likely Mohs hardness about 6–7, no obvious cleavage, and specific gravity roughly 2.6–2.8.
Identified More igneous →
Explore Weathered rounded pebble in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Fine- to medium-grained, tan-brown, dull to weakly earthy luster, with diffuse pale and darker mineral patches; likely Mohs hardness about 6–7, no obvious cleavage, and specific gravity roughly 2.6–2.8.
Formation & geological history
Probably a naturally weathered and water-rounded fragment derived from continental felsic bedrock, potentially glacial or stream transported. The background appears to show banded gneiss, suggesting a metamorphic source, but the pebble itself lacks sufficient visible texture for confident classification.
Uses & applications
Common pebbles have little commercial value, though similar granite and gneiss are used as aggregate, landscaping stone, and building or paving material.
Geological facts
Its smooth shape indicates abrasion during transport, while the rusty brown color likely reflects iron-oxide weathering of ferromagnesian minerals or mica.
Field identification & locations
Inspect a fresh fracture with a hand lens: visible quartz, feldspar, and mica would support granite/gneiss; a streak test is usually white, and it should not scratch glass reliably unless quartz-rich. Common worldwide in stream beds, beaches, glacial deposits, and weathered outcrops.
