sedimentary

Iron-oxide-stained river pebble

Likely iron-stained quartzite or chert; exact identification is uncertain from the photograph.

AI-generated identification · may be incorrect

Rounded, brown to ochre surface with a subdued luster. If quartz-rich, hardness is about 7 Mohs; no obvious cleavage and a fine-grained or compact texture.

Identified October 16, 2026More sedimentary →

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Physical properties

Rounded, brown to ochre surface with a subdued luster. If quartz-rich, hardness is about 7 Mohs; no obvious cleavage and a fine-grained or compact texture.

Formation & geological history

Likely formed from a resistant rock fragment, rounded by transport in water, with brown coloration from iron-oxide staining. Its geological age and original formation environment cannot be determined from the image.

Uses & applications

Primarily a natural collectible or decorative pebble; quartzite and chert can also be used as aggregate or, historically, for tools.

Geological facts

Iron oxides such as hematite and goethite commonly produce rusty brown, yellow, and red staining on rocks.

Field identification & locations

Its smooth, rounded shape suggests water wear; a hardness or streak test and close inspection of a fresh surface would help distinguish quartzite, chert, and other possibilities.