8.5" Polished, Agate Replaced Wood Slab - Oregon
Here is a beautiful, 8.5" wide, polished slab of chalcedony (agate) replaced petrified wood from the Eocene age Stinking Water Creek deposits of Oregon. It displays fabulous, rich orange hues and fascinating wood grain detail in spots. This specimen has been cut flat on both sides and polished to a glossy finish.
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.