sedimentary

Rounded river pebble

Unidentified fine-grained clastic rock, possibly sandstone or mudstone

AI-generated identification · may be incorrect

Olive-brown, dull earthy luster, smooth water-worn surface, and no visible crystals or cleavage. Hardness and specific gravity cannot be determined reliably from the image; likely about Mohs 3–6 depending on composition.

Identified August 28, 2026More sedimentary →

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Physical properties

Formation & geological history

Likely a naturally weathered and stream-rounded clast transported by water; its original rock may be sedimentary, volcanic, or metamorphic. Geological age is indeterminate from appearance alone.

Uses & applications

Primarily a decorative, craft, landscaping, or teaching specimen; it has little commercial or jewelry value unless distinctive composition or provenance is established.

Geological facts

The smooth oval shape records abrasion during transport, commonly in rivers, beaches, or glacial environments. Surface color may reflect iron-bearing minerals or weathering.

Field identification & locations

Field identification requires a fresh broken surface, grain inspection, streak, hardness, acid reaction, and locality information; the image alone cannot distinguish sandstone from basalt, slate, or other fine-grained rocks. Common worldwide in streambeds and beaches.