After considerable discussion about minerals, rocks and gems, the Mississippi State Legislature recognized Petrified Wood as the state stone on May 14, 1976.
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Petrified Wood in Mississippi comes in several varieties: a nondescript type called "silicified wood," a denser type called "massive silicified wood," and a third type known as "petrified palm wood." Because it is difficult to know exactly which trees these woods came from, they are assigned to paleobotanical form genera with the suffix -oxylon (meaning "looks like") -- hence wood which resembles that of modern palms is called Palmoxylon, but may or may not be from trees closely related to modern palms. Most of the best petrified wood from Mississippi comes from trees which grew in the state during the Oligocene Epoch, around 30 million years ago. The Gulf of Mexico's shoreline extended further north at that time, which explains why the wood is found in the more northern parts of the state. The only one of its kind in the eastern half of the United States, the Mississippi Petrified Forest is a privately-owned Registered National Landmark featuring 35-million-year-old fossilized logs. Once part of a massive primeval forest, the trees were uprooted by a large flood that eventually turned the wood into stone at the bottom of the river. Most of the logs are now between five and 10 feet long, but they were over 100 feet high and perhaps 1000 years old.
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