metamorphic

Rounded gray-green pebble, possibly serpentinite

Unidentified greenish metamorphic rock; serpentinite is a tentative visual match

AI-generated identification · may be incorrect

Fine-grained, dull to slightly waxy surface with rounded, weathered edges. Hardness, mineral composition, and crystal structure cannot be reliably determined from the photo.

Identified September 30, 2026More metamorphic →

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Physical properties

Fine-grained, dull to slightly waxy surface with rounded, weathered edges. Hardness, mineral composition, and crystal structure cannot be reliably determined from the photo.

Formation & geological history

Likely a water-worn natural pebble; if serpentinite, it formed by alteration of ultramafic rock, commonly during ancient seafloor or mountain-building processes. Age and exact formation environment are unknown.

Uses & applications

No distinctive commercial or jewelry use is apparent; mainly suitable as a teaching or collected specimen.

Geological facts

The subdued green-gray color can occur in several unrelated rocks, so color alone is not diagnostic.

Field identification & locations

Check for a waxy feel, green streaks, or fibrous veins to assess serpentinite; a hardness and streak test, or mineral analysis, would help identify it. Similar pebbles occur in river and beach gravels worldwide.