fossil

Fossilized bone or bone fragment

Indeterminate fossil bone; mineralized apatite (hydroxyapatite), commonly Ca₅(PO₄)₃(OH)

AI-generated identification · may be incorrect

Brown, elongated, rounded specimen with a granular, porous surface consistent with mineralized bone; exact hardness and density cannot be measured from the image. Fossil bone typically has Mohs hardness about 5, dull to earthy luster, and retains cellular or vascular pores.

Identified September 4, 2026More fossil →

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Physical properties

Formation & geological history

Likely originally vertebrate bone later permineralized as groundwater replaced pore spaces with silica, calcite, or iron oxides; its geological age and species are undetermined. The smooth shape may result from natural abrasion or later handling.

Uses & applications

Primarily a teaching or collecting specimen; not generally used in construction or jewelry unless cut and polished as decorative fossil material.

Geological facts

The darker brown coloration commonly reflects iron-oxide staining. Genuine fossil bone often shows a contrasting internal pattern or tiny vascular channels when freshly broken or polished.

Field identification & locations

Look for recognizable porous/cellular structure, a heavier-than-modern-bone feel, and mineral-filled pores; a streak, density test, or microscopy would help distinguish it from ordinary stone or cast material. Fossil bones occur in sedimentary deposits worldwide.