metamorphic

Weathered metamorphic pebble, likely gneiss

Foliated quartz–feldspar rock, provisionally gneiss

AI-generated identification · may be incorrect

Rounded, water-worn pebble with mottled gray, cream, and rusty-brown patches and weak light-dark banding. Likely quartz and feldspar with dark mica or amphibole; hardness about 6–7 Mohs, vitreous to dull luster, interlocking crystals, and no obvious cleavage at this scale.

Identified October 11, 2026More metamorphic →

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Physical properties

Formation & geological history

Likely formed when older rock was recrystallized under heat and pressure, then exposed and rounded by transport in a stream or shoreline. Its geological age cannot be determined from the image.

Uses & applications

As a small pebble, mainly suitable for collecting or decoration; gneiss is also used as dimension stone, paving, and aggregate.

Geological facts

Rusty areas may be iron-oxide staining from weathering. The photo does not show enough detail to confirm gneiss or distinguish it from other metamorphic rocks.

Field identification & locations

Look for persistent alternating mineral bands and interlocking grains on a fresh surface; compare with local bedrock or use a hand lens. Gneiss occurs worldwide in ancient continental crust.