fossil

Fossilized bone fragment

Mineralized vertebrate bone, commonly hydroxyapatite partly replaced by silica or calcite

AI-generated identification · may be incorrect

Tan-brown, porous, irregular specimen with possible cortical and cancellous bone texture; hardness typically 3–6 Mohs depending on mineral replacement, dull to earthy luster, no consistent cleavage. The image is insufficient for species-level identification.

Identified August 15, 2026More fossil →

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Physical properties

Formation & geological history

Formed when buried bone is mineralized during diagenesis, usually by groundwater carrying silica, calcite, or iron minerals; age may range from thousands to millions of years. Common in sedimentary deposits, river gravels, caves, and fossil beds.

Uses & applications

Primarily a collecting, educational, and research specimen; rarely used ornamentally. Value depends strongly on completeness, provenance, age, and taxonomic identification.

Geological facts

The porous internal structure and joint-like broken form are more consistent with fossil bone than ordinary stone, though weathered wood or concretion is possible.

Field identification & locations

Look for cellular pores, layered cortical bone, and a denser outer surface; compare freshly broken areas and use a hand lens. Common sources include western North America, the Badlands, deserts, and gravel deposits.