What Is Petrified Wood?
The word, to petrify, literally means, "turn to stone." Petrified wood, then, is wood that has turned to stone. The English word is similar to the Greek (piedra) and Latin (pietra) words for stone.
Petrified wood is a fossil of a woody plant preserved by permineralization through time by chemical and physical processes. In some cases, fossilized wood is readily identifiable. Generally, the species can be determined by examining thin slices of the fossil under a microscope. The microscopic structure of the fossilized wood is then compared to the cellular structure of living species.