Petrified Wood

Petrified wood is the fossilized remains of land based vegetation, namely trees. Trees first appeared on the planet about 350 million years ago, and remains of this flora are still some of the more common fossil plant remnants, The organic material within the wood is often replaced by standard surrounding sedimentary rock, but can also be intruded by gem stones or minerals such as quartz, chalcedony, or even opal.