4.6" Petrified Wood (Araucioxylon) - Circle Cliffs, Utah
This is a 4.6" piece of petrified wood (Araucarioylon arizonicum) from the Chinle Formation, Garfield County, Utah. This piece is polished on one side, highlighting the color of the inclusions that occur during fossilization.
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.