sedimentary

Rounded iron-rich river pebble, likely sandstone or ironstone

Indeterminate ferruginous sandstone/ironstone; exact identification requires closer examination

AI-generated identification · may be incorrect

Brown, rounded, fine-grained surface with scattered pale grains and a dull to slightly earthy luster. Hardness and mineral composition cannot be determined reliably from the photo; ferruginous sandstone is typically quartz-rich and about 6–7 Mohs.

Identified October 7, 2026More sedimentary →

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Physical properties

Formation & geological history

Likely a sedimentary fragment cemented or stained by iron oxides, then rounded by transport in water or abrasion. Its age and precise formation environment cannot be established from appearance alone.

Uses & applications

Primarily a natural collectible or landscaping pebble; no evident gem or industrial value.

Geological facts

Iron oxides such as hematite and goethite give many sedimentary rocks their reddish-brown color.

Field identification & locations

The smooth, waterworn shape suggests transport, but a fresh break, hardness test, and close inspection of grain size would help distinguish sandstone from ironstone or another pebble. Similar pebbles occur in stream and glacial deposits worldwide.