metamorphic

Rounded, banded metamorphic cobble

Likely gneiss or foliated quartz-rich metamorphic rock; exact identification is uncertain from the photograph.

AI-generated identification · may be incorrect

Gray and pale tan, fine- to medium-grained, with wavy light and dark bands and a smooth, water-worn surface. Likely dominated by quartz and feldspar with darker mica or other minerals; hardness and cleavage cannot be reliably determined from the image.

Identified September 25, 2026More metamorphic →

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Physical properties

Formation & geological history

The banding likely formed when an original rock was recrystallized and segregated under heat and pressure, then the stone was rounded by transport in water. Its age and original setting cannot be determined visually.

Uses & applications

Primarily a natural collectible or decorative stone; similar durable material may be used for landscaping and paving.

Geological facts

The rounded shape and visible banding are consistent with a river or beach cobble, but neither the exact rock type nor provenance can be confirmed from a photo.

Field identification & locations

Look for persistent, alternating mineral bands and a dense, hard texture; a fresh broken surface or mineral tests would help distinguish gneiss from other banded rocks. Banded metamorphic cobbles occur in many regions with exposed metamorphic bedrock.