Rock Identifier
Fossilized bone fragment (Mineral-replaced vertebrate bone, commonly apatite [Ca₅(PO₄)₃(F,OH,Cl)]) — fossil
fossil

Fossilized bone fragment

Mineral-replaced vertebrate bone, commonly apatite [Ca₅(PO₄)₃(F,OH,Cl)]

AI-generated identification · may be incorrect

Tan-brown, elongated and weathered, with a dense matte surface and possible porous or fibrous internal texture; fossil bone is typically Mohs 5–6 and has a specific gravity around 2.8–3.2. The shape may represent a fragment of limb bone, rib, or tooth, but the image is insufficient for species-level identification.

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Physical properties

Tan-brown, elongated and weathered, with a dense matte surface and possible porous or fibrous internal texture; fossil bone is typically Mohs 5–6 and has a specific gravity around 2.8–3.2. The shape may represent a fragment of limb bone, rib, or tooth, but the image is insufficient for species-level identification.

Formation & geological history

Original bone was buried in sediment and gradually mineralized through permineralization or replacement, often during the Mesozoic or Cenozoic; its exact age cannot be determined visually. Common fossil-bearing environments include river channels, floodplains, caves, and marine sediments.

Uses & applications

Primarily a collecting, educational, and research specimen; polished fossil bone may be used decoratively or in jewelry. It has little industrial use.

Geological facts

Fossil bone can retain microscopic vascular canals and may fluoresce under ultraviolet light depending on mineral content. A broken surface often reveals a porous interior unlike ordinary stone.

Field identification & locations

Look for repeated bone-like pores, longitudinal structure, irregular cortical thickness, and a heavier, more mineral-like feel than modern bone; a qualified paleontologist should confirm it. Found worldwide in sedimentary deposits.

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Bioclastic limestone, composed chiefly of calcite (CaCO₃)

sedimentary
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Porous limestone pebble

Calcite-rich limestone (primarily CaCO₃); exact identification is uncertain from the image

sedimentary
Weathered fossil bone fragment (identification uncertain) (Fossilized bone; exact taxon and mineral composition cannot be determined from the image) — fossil

Weathered fossil bone fragment (identification uncertain)

Fossilized bone; exact taxon and mineral composition cannot be determined from the image

fossil