Rock Identifier
Fossilized bone fragment (Petrified bone, mineral-replaced vertebrate bone; exact taxon indeterminate) — fossil
fossil

Fossilized bone fragment

Petrified bone, mineral-replaced vertebrate bone; exact taxon indeterminate

AI-generated identification · may be incorrect

Tan to brown, porous specimen with elongated internal striations and a dense outer cortex; likely hardness about 5–7 Mohs, dull to slightly vitreous luster, and no obvious cleavage. The visible vascular/cancellous texture supports bone rather than ordinary rock.

Identified More fossil →
Explore Fossilized bone fragment in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App StoreGoogle Play

Physical properties

Tan to brown, porous specimen with elongated internal striations and a dense outer cortex; likely hardness about 5–7 Mohs, dull to slightly vitreous luster, and no obvious cleavage. The visible vascular/cancellous texture supports bone rather than ordinary rock.

Formation & geological history

Originally vertebrate bone later buried and permineralized as groundwater deposited silica, calcite, or iron oxides in its pores; age cannot be determined from the photograph and may range from Paleozoic to Cenozoic.

Uses & applications

Primarily a collecting, educational, and decorative specimen; polished petrified bone is sometimes used in cabochons and small carvings, but it has little industrial use.

Geological facts

Fossil bone commonly preserves a porous honeycomb or vascular pattern, often enhanced by brown, red, or black mineral staining. It is distinct from ordinary petrified wood, which typically shows wood grain and growth rings.

Field identification & locations

Inspect for a porous cortical/interior structure, mineral-filled channels, and consistent replacement rather than fresh organic tissue; common sources include western North America, Madagascar, and Australia. Exact identification requires locality and possibly microscopy.

More like this

Other fossil specimens

Probable fossil-bearing rock or mineral concretion (Unidentified carbonate-rich concretion with a possible fossil inclusion) — fossil

Probable fossil-bearing rock or mineral concretion

Unidentified carbonate-rich concretion with a possible fossil inclusion

fossil
Likely fossil oyster shell (Fossilized bivalve shell; exact species cannot be identified from the image) — fossil

Likely fossil oyster shell

Fossilized bivalve shell; exact species cannot be identified from the image

fossil
Crinoid Stem Fossil in Matrix (Phylum Echinodermata, Class Crinoidea) — fossil

Crinoid Stem Fossil in Matrix

Phylum Echinodermata, Class Crinoidea

fossil
Fossiliferous limestone (likely a crinoidal or shell-fragment limestone) (Bioclastic limestone, composed chiefly of calcite (CaCO₃)) — sedimentary

Fossiliferous limestone (likely a crinoidal or shell-fragment limestone)

Bioclastic limestone, composed chiefly of calcite (CaCO₃)

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

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