sedimentary

Petrified Wood

Silicified Wood (SiO2)

Hardness of 7 on the Mohs scale, earthy to vitreous luster, preserves original cellular wood structure, colors include browns, reds, and yellows.

Identified November 14, 2026More sedimentary →

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Physical properties

Hardness of 7 on the Mohs scale, earthy to vitreous luster, preserves original cellular wood structure, colors include browns, reds, and yellows.

Formed when buried wood is slowly replaced by minerals like quartz via groundwater over millions of years.

Used in ornamental carvings, jewelry making, lapidary art, and sought after by fossil collectors worldwide.

Petrified wood is the state fossil of several U.S. states and can retain microscopic cellular detail of ancient trees.

Identify by its distinct tree-ring patterns combined with a stone-like weight and hardness that scratches glass.

Fossil-bearing concretion, possibly containing a fossil shell or other organic inclusion

Calcareous concretion; exact fossil and host-rock composition are not identifiable from the image

Sandstone or Siltstone

Arenite (if sandstone)

Fossiliferous Sedimentary Rock

Sedimentary limestone with invertebrate fossil imprint

Shale

Fissile Sedimentary Rock

Sandstone

Arenite

Shale

Clastic sedimentary rock