sedimentary

Rounded brown river pebble

Likely weathered quartz-rich sandstone or iron-stained quartzite; exact identification requires testing

AI-generated identification · may be incorrect

Fine-grained, dull to slightly earthy luster, brown-gray with a rusty band, and smoothly rounded by abrasion. Likely Mohs hardness about 6–7 if quartz-rich; noncleaving and moderately dense.

Identified August 17, 2026More sedimentary →

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Physical properties

Fine-grained, dull to slightly earthy luster, brown-gray with a rusty band, and smoothly rounded by abrasion. Likely Mohs hardness about 6–7 if quartz-rich; noncleaving and moderately dense.

Formation & geological history

Formed from quartz-rich sediment lithified into sandstone or metamorphosed into quartzite, then weathered and transported in a stream or shoreline environment. Its precise geological age cannot be determined from the photograph.

Uses & applications

Primarily a natural collectible or decorative pebble; if quartzite, it can serve as aggregate or construction stone, though this small specimen has no practical industrial value.

Geological facts

The smooth shape and subdued surface indicate prolonged mechanical abrasion and weathering. The orange-brown coloration is probably caused by iron-oxide staining.

Field identification & locations

Common in rivers, beaches, and glacial deposits worldwide. A glass-scratch test, streak test, and close inspection for visible sand grains or interlocking quartz would help distinguish sandstone from quartzite.