This petrified wood is over 80,000,000 years old. The trees originally grew in the Triassic Period. After the tree died, it was buried by sediment and saturated with water rich in silica. Eventually the makeup of the wood was replaced by silica and various other minerals and the logs changed to stone. The beautiful coloring of the wood is due to traces of iron, manganese and carbon that stained the silica. Over time, the sediment covering the wood was removed exposing the petrified logs. Petrified wood also makes an attractive gemstone used to make jewelry. This petrified wood is from Arizona.