sedimentary

Rounded yellow-brown chert or jasper pebble

Microcrystalline quartz (SiO₂), likely iron-stained chert/jasper

AI-generated identification · may be incorrect

Smooth water-worn pebble with mustard-yellow, brown, and gray mottling; dull to waxy luster and no visible cleavage. Quartz hardness is about 7 Mohs; specific gravity approximately 2.6, though the exact texture is uncertain from the image.

Identified September 8, 2026More sedimentary →

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Physical properties

Formation & geological history

Likely silica-rich sedimentary material formed by replacement or cementation, with iron oxides producing the yellow-brown colors, then rounded by stream or shoreline transport. Such pebbles are common glacial or alluvial deposits in northern Ohio; age is indeterminate.

Uses & applications

Used as lapidary material, tumbled stones, cabochons, and decorative aggregate; generally not valuable as an uncut pebble.

Geological facts

The appearance could also represent iron-stained quartzite or a dense silicified limestone; a scratch test and fresh broken surface would distinguish them better.

Field identification & locations

Common around Lake Erie beaches, glacial gravels, and streams near 41.9°N, 80.6°W. It should resist scratching by a steel knife and may scratch ordinary glass; no fizz with dilute acid supports chert, while strong fizz suggests calcite-rich rock.