fossil

Peanut Wood (Fossilized Wood in Radiolarite)

Petrified Wood (Silicified)

Hardness 6.5-7, brown/black matrix with white/cream distinct peanut-shaped markings, vitreous luster when polished.

Identified August 19, 2026More fossil →

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Physical properties

Hardness 6.5-7, brown/black matrix with white/cream distinct peanut-shaped markings, vitreous luster when polished.

Formed when pieces of wood were washed into the ocean, bored by marine wood-boring bivalves (Teredo), and then fossilized with silica.

Commonly used in lapidary, cabochons, and jewelry making.

The 'peanuts' are actually the boreholes made by ancient shipworms, which were later filled with lighter-colored radiolarite before fossilization.

Found mainly in Western Australia (Kennedy Ranges). Identified by the contrasting peanut-shaped inclusions in a darker matrix.

Probable fossil-bearing rock or mineral concretion

Unidentified carbonate-rich concretion with a possible fossil inclusion

Likely fossil oyster shell

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

Crinoid Stem Fossil in Matrix

Phylum Echinodermata, Class Crinoidea

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

Bioclastic limestone, composed chiefly of calcite (CaCO₃)

Porous limestone pebble

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

Weathered fossil bone fragment (identification uncertain)

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