fossil
Petrified Wood
Silicified Wood (SiO2 permineralization)
Hardness: 6.5-7 (Mohs scale), Color: tan, brown, white, cream with wood-like grain, Luster: vitreous to dull, Structure: cryptocrystalline, Cleavage: none (conchoidal fracture).
- Hardness
- 6
Identified More fossil →
Explore Petrified Wood in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6.5-7 (Mohs scale), Color: tan, brown, white, cream with wood-like grain, Luster: vitreous to dull, Structure: cryptocrystalline, Cleavage: none (conchoidal fracture).
Formation & geological history
Formed through permineralization where organic wood material is replaced by silica (usually chalcedony or quartz) from groundwater, often after burial by volcanic ash or sediment millions of years ago.
Uses & applications
Display specimens, lapidary work (jewelry, bookends, furniture), and educational collection.
Geological facts
The colors in petrified wood are caused by trace elements; for example, iron produces reds/browns, while manganese creates pinks/blacks. The Arizona Petrified Forest is one of the most famous global sites.
Field identification & locations
Identify by looking for visible growth rings, bark textures, or fiber-like patterns. It will feel much heavier and colder than real wood and cannot be scratched by a steel blade.
More like this
Other fossil specimens
Crinoid Stem Fossil in Matrix
Phylum Echinodermata, Class Crinoidea
fossil
Sedimentary Outcrop (Sandstone/Shale)
Sedimentary bedrock formation (variable composition)
sedimentary
Chert with Fossil Brachiopod
Microcrystalline Quartz (SiO2) with Calcitic Brachiopod inclusion
sedimentary
Fossiliferous Limestone
Fossiliferous Calcilutite / Biomicrite
sedimentary
Fossiliferous Limestone
Biogenic Limestone with Brachiopod/Crinoid fragments
sedimentary
Horn Coral (Rugose Coral)
Order Rugosa (extinct)
fossil