metamorphic
Banded metamorphic pebble, likely gneiss
Quartz–feldspar–mica gneiss (tentative identification)
AI-generated identification · may be incorrectRounded gray, cream, and dark wavy bands suggest mineral segregation; likely quartz and feldspar with dark mica or amphibole. These minerals are typically Mohs 6–7, with vitreous to dull luster; the image alone cannot confirm composition or crystal structure.
Identified More metamorphic →
Explore Banded metamorphic pebble, likely gneiss in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Rounded gray, cream, and dark wavy bands suggest mineral segregation; likely quartz and feldspar with dark mica or amphibole. These minerals are typically Mohs 6–7, with vitreous to dull luster; the image alone cannot confirm composition or crystal structure.
Formation & geological history
Gneiss forms when pre-existing rock is recrystallized and banded under high heat and pressure during mountain-building. Its age and exact formation history cannot be determined from the photograph.
Uses & applications
This small pebble is mainly suitable for collecting or display; gneiss is also used as dimension stone and aggregate.
Geological facts
The concentric-looking pattern may be folded or irregular gneissic banding, though weathering or another rock type could produce a similar appearance.
Field identification & locations
Check for alternating light and dark mineral bands and a granular crystalline texture; similar pebbles occur in streams and glacial deposits sourced from metamorphic terrain.
More like this
