fossil

Fossilized bone fragment (probable mammal bone)

Mineralized bone; taxonomic identification requires microscopy and preparation

AI-generated identification · may be incorrect

Irregular 4 cm fragment with porous, pitted texture and gray-brown coloration, consistent with mineralized bone rather than a crystalline rock. Likely hardness about 3–5 Mohs; luster dull, with no visible cleavage or crystal faces; apparent weight is consistent with a dense river-worn fossil.

Identified September 1, 2026More fossil →

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Physical properties

Formation & geological history

Likely an older bone fossil mineralized by groundwater, commonly through replacement or filling of pores with silica, calcite, or iron-bearing minerals. Its geological age cannot be determined from the photograph; Río de la Plata sediments range from young Quaternary deposits to reworked older material.

Uses & applications

Primarily a collecting and educational specimen; fossil bone may be used in paleontological research. It has little industrial or jewelry value.

Geological facts

The raised knobs and porous internal texture resemble a fragment of vertebrate bone, possibly a joint or compact-bone section. It is not possible to identify the animal reliably from this image.

Field identification & locations

Look for a cellular/trabecular interior, cortical outer layer, and irregular vascular pores; compare with modern bone and avoid acid or polishing. Río de la Plata beaches and dredged sediments can contain reworked fossil bones, but local confirmation is needed.