fossil

Petrified Wood

Silicified wood (SiO2)

Hardness of 7 on the Mohs scale, varied Earth-tone colors, vitreous to waxy luster, amorphous crystal structure, specific gravity around 2.65.

Identified October 20, 2026More fossil →

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Physical properties

Hardness of 7 on the Mohs scale, varied Earth-tone colors, vitreous to waxy luster, amorphous crystal structure, specific gravity around 2.65.

Formed via permineralization where organic material is buried in sediment and replaced by silica-rich groundwater over millions of years.

Used for ornamental carvings, decorative tabletops, lapidary art, and sought after by fossil collectors.

The cellular structure of the original tree is often perfectly preserved, allowing scientists to identify ancient plant species.

Identify by its distinct wood grain patterns coupled with a stone-like weight and hardness; commonly found in arid regions and ancient riverbeds.

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

Fossil oyster shell

Oyster (family Ostreidae); shell composed chiefly of calcite (CaCO₃)