sedimentary
Petrified Wood
Silicified wood (Silicon dioxide, SiO2)
AI-generated identification · may be incorrectMohs hardness of 7, vitreous to waxy luster, amorphous crystal structure (microcrystalline quartz), and preserved cellular wood grain colors.
Identified More sedimentary →
Explore Petrified Wood in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Mohs hardness of 7, vitreous to waxy luster, amorphous crystal structure (microcrystalline quartz), and preserved cellular wood grain colors.
Formation & geological history
Formed via permineralization when buried organic wood is slowly replaced by silica-rich groundwater over millions of years.
Uses & applications
Used primarily in lapidary arts, decorative bookends, high-end jewelry, and as collector display specimens.
Geological facts
The oldest petrified wood deposits date back over 300 million years to the Carboniferous period.
Field identification & locations
Identify by retaining the distinct growth rings and bark texture of original wood while feeling unusually heavy and cold.
More like this
Other sedimentary specimens
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
fossil
Fossiliferous Sedimentary Rock
Sedimentary limestone with invertebrate fossil imprint
fossil
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Sandstone
Arenite
sedimentary
Shale
Shale (clastic sedimentary rock)
sedimentary
Shale (or Mudstone/Siltstone)
Sedimentary Mudrock (SiO2, Al2O3 base with clay minerals)
sedimentary