sedimentary

Rounded iron-rich pebble

Likely ferruginous sandstone or ironstone pebble; exact identification requires testing

AI-generated identification · may be incorrect

Brown to rusty orange, dull earthy luster, rounded water-worn shape, and dark vein-like markings with pale gray patches. Likely hardness about 5–7 Mohs; granular texture and no obvious cleavage, with density potentially elevated by iron oxides.

Identified August 19, 2026More sedimentary →

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Physical properties

Formation & geological history

Probably formed from iron-cemented sediment or weathered iron-rich rock, then rounded by stream, beach, or glacial transport. Its precise geological age and provenance cannot be determined visually.

Uses & applications

Primarily a natural collectible or teaching specimen; ironstone and ferruginous sandstone may be used locally as aggregate or dimension stone, but this pebble has little industrial value.

Geological facts

Rusty coloration commonly comes from hematite and goethite coatings or cement. The dark lines may be manganese-oxide staining, fractures, or mineral-filled veins rather than fossils.

Field identification & locations

Look for a rusty streak, weak-to-strong attraction to a magnet, and granular sedimentary texture; a streak test, hardness test, and acid test would help distinguish ironstone from basalt or chert. Common in stream gravels, beaches, and glacial deposits.