Rock Identifier
Fossilized bone fragment (probable large mammal bone) (Mineralized vertebrate bone; commonly hydroxyapatite, Ca₅(PO₄)₃(OH), partly replaced by silica or calcite) — fossil
fossil

Fossilized bone fragment (probable large mammal bone)

Mineralized vertebrate bone; commonly hydroxyapatite, Ca₅(PO₄)₃(OH), partly replaced by silica or calcite

AI-generated identification · may be incorrect

Tan-brown, porous and fibrous with apparent cortical texture; hardness commonly about 3–5 when mineralized, variable luster, and no regular crystal cleavage. The shape and texture resemble a weathered bone fragment, though a photograph cannot confirm identification.

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Physical properties

Tan-brown, porous and fibrous with apparent cortical texture; hardness commonly about 3–5 when mineralized, variable luster, and no regular crystal cleavage. The shape and texture resemble a weathered bone fragment, though a photograph cannot confirm identification.

Formation & geological history

Buried bone undergoes fossilization as groundwater minerals replace or fill its pores over thousands to millions of years; age and species are indeterminate from the image. It likely formed in sedimentary deposits such as river, cave, or floodplain sediments.

Uses & applications

Used for educational display, paleontological study, and collecting; value depends mainly on confirmed species, provenance, completeness, and legal documentation.

Geological facts

Bone often retains a distinctive vascular pore pattern and dense outer cortex; a fresh broken surface may reveal contrasting porous interior and fibrous structure.

Field identification & locations

Inspect for repeating vascular canals and a porous interior; compare density with ordinary limestone and avoid destructive testing. Common fossil bones occur in the western United States, Africa, and many sedimentary basins worldwide.

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Bioclastic limestone, composed chiefly of calcite (CaCO₃)

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

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Weathered fossil bone fragment (identification uncertain)

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

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