This petrified wood was found in Texas. Each piece is between 8 1/4 inches and 10 inches long. You can think of petrified wood as a fossil, but not from the remains of an animal. Instead, petrified wood is created from the remains of trees. Once a tree either dies or is buried by a natural disaster such as a mudslide or flash flood, the organic material is replaced with heavier and denser minerals that were in the ground where the tree was buried. Petrified wood has been discovered in the most unlikely of places such as the deserts of North America and Antarctica. Some of the oldest petrified wood ever found can be dated back as far as 385 million years during the Devonian period. This is the time when the first terrestrial vertebrates as well as wingless insects came about.