igneous
Rounded granite or granitic gneiss pebble
Granite; mainly quartz, feldspar, and mica, possibly with metamorphic foliation
AI-generated identification · may be incorrectCoarse-grained, speckled gray-beige surface with dark mica/minerals; likely Mohs 6–7, vitreous to dull luster, no obvious cleavage as a whole, and granular interlocking crystals. The rounded shape indicates water or glacial abrasion.
Identified More igneous →
Explore Rounded granite or granitic gneiss pebble in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Coarse-grained, speckled gray-beige surface with dark mica/minerals; likely Mohs 6–7, vitreous to dull luster, no obvious cleavage as a whole, and granular interlocking crystals. The rounded shape indicates water or glacial abrasion.
Formation & geological history
Formed by slow cooling of silica-rich magma deep underground, or possibly recrystallized as gneiss during metamorphism; commonly Precambrian to younger, depending on source terrain. Later weathering and transport rounded it into a pebble.
Uses & applications
Common granite is used for building stone, countertops, monuments, aggregate, and landscaping; this small specimen has mainly educational or decorative value.
Geological facts
Granite’s visible crystals record slow subterranean cooling. A strong acid reaction would be unexpected, while a steel scratch should generally fail on quartz-rich grains.
Field identification & locations
Look for interlocking white or pink feldspar, translucent gray quartz, and black mica; gneiss may show banding, though this specimen is too weathered for certainty. Common in streambeds, beaches, glacial deposits, and areas underlain by granite.
