fossil

Petrified Wood

Silicified Wood (SiO2)

Hardness of 7 on the Mohs scale, waxy to vitreous luster, amorphous quartz structure, colors range from brown to red due to iron oxides.

Identified October 30, 2026More fossil →

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Physical properties

Hardness of 7 on the Mohs scale, waxy to vitreous luster, amorphous quartz structure, colors range from brown to red due to iron oxides.

Formed when buried organic wood is slowly replaced by silica-rich groundwater over millions of years, often dating from the Triassic period onward.

Used primarily for ornamental carvings, polished display slabs, and collector specimens.

The petrification process preserves the original cellular structure of the tree down to microscopic details.

Identify by wood grain patterns combined with conchoidal fracture and high hardness that scratches glass; found worldwide.

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