This Specimen has been sold.
Petrified Wood Limb From Washington
This is a limb of petrified wood from Washington State which is Miocene in age. The limb has been cut and polished on one side to reveal the inner structure including growth rings.
Petrified wood is the name given to wood that has been turned into stone (fossilized) through the process of permineralization. All of the organic matter becomes replaced by minerals, while much of the original structure such as tree rings in retained. For this to happen the wood needs to be buried in an environment both low in oxygen (preventing decomposition) and with flowing, mineral-laden water. The coloration is due to the various minerals that are present during fossilization. For example red colors are due to iron compounds, greens due to copper, etc.