igneous
Rounded quartz-rich pebble, likely granite or granitic gneiss
Granite/granitic rock composed mainly of quartz (SiO₂), feldspar, and minor dark mica or amphibole
AI-generated identification · may be incorrectPale gray-beige, granular texture, dull to weakly vitreous luster, and irregular massive structure; quartz has Mohs hardness 7, while feldspar is about 6. No obvious cleavage is visible in the rounded specimen.
Identified More igneous →
Explore Rounded quartz-rich pebble, likely granite or granitic gneiss in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Pale gray-beige, granular texture, dull to weakly vitreous luster, and irregular massive structure; quartz has Mohs hardness 7, while feldspar is about 6. No obvious cleavage is visible in the rounded specimen.
Formation & geological history
Likely weathered and stream-rounded from an igneous or metamorphic source rock, generally formed deep in Earth’s crust during Precambrian to Phanerozoic geologic time. The visible rounding indicates transport by water or glacial action.
Uses & applications
Common granitic material is used for crushed aggregate, building stone, countertops, monuments, and landscaping; this small specimen has mainly educational or modest collecting value.
Geological facts
The dark specks may be biotite mica, hornblende, or iron-oxide staining. A fresh broken surface would better reveal whether the rock is granite, gneiss, or quartz-rich vein material.
Field identification & locations
Look for interlocking grains of translucent quartz, white or pink feldspar, and black mica; a glass scratch test can confirm quartz, though it may damage the specimen. Common worldwide, especially in stream gravels derived from granitic bedrock.
