sedimentary

Rounded gray pebble

Unidentified lithic pebble; likely quartz-rich sandstone, quartzite, or fine-grained igneous rock

AI-generated identification · may be incorrect

Small, water-worn, subrounded gray specimen with a dull to weakly silky luster and no visible crystals or cleavage. Hardness cannot be determined reliably from the image; likely about Mohs 6–7 if quartz-rich.

Identified August 30, 2026More sedimentary →

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Physical properties

Formation & geological history

Most likely a naturally weathered and transported pebble formed by erosion in a stream, beach, or gravel deposit; its original rock age and formation environment cannot be established visually.

Uses & applications

Primarily a curiosity, teaching sample, or decorative pebble; too small and unidentified for practical construction or jewelry use. Value is negligible unless laboratory testing reveals an unusual material.

Geological facts

The smooth shape indicates abrasion during transport or tumbling. Gray color alone is insufficient to distinguish quartzite, sandstone, basalt, slate, or other common rocks.

Field identification & locations

Check streak, hardness, grain texture, magnetism, acid reaction, and specific gravity; a hand lens may reveal quartz grains or basaltic texture. Common analogous pebbles occur worldwide in riverbeds, beaches, and glacial gravels.