Petrified Wood, 300 Million Years Old Fossil. Petrified wood, also known as petrified tree from Ancient Greek p? A meaning’rock’ or’stone'; literally’wood turned into stone’, is the name given to a special type of fossilized wood, the fossilized remains of terrestrial vegetation. Which occurs over million’s of years and are categorize if 15 to 300 million years old. Petrifaction is the result of a tree or tree-like plants having been replaced by stone via a mineralization process that often includes permineralization and replacement. The organic materials making up cell walls have been replicated with minerals (mostly silica in the form of opal, chalcedony, or quartz). In some instances, the original structure of the stem tissue may be partially retained. Unlike other plant fossils, which are typically impressions or compressions, petrified wood is a three-dimensional representation of the original organic material.