PETRIFIED WOOD
Petrifaction is the process of organic material fossilizing. It is the result of a tree or plant having completely transitioned to stone by the process of permineralization. All the organic materials have been replaced with minerals, while retaining the original structure of the wood. Unlike other types of fossils which are typically impressions or compressions, petrified wood is a three-dimensional representation of the original organic material.
In some areas, entire forests have petrified and are now preserved as national parks.