Polished Petrified Wood Mineral
Highly polished petrified wood from Zimbabwe. This piece which could date back as far as two hundred million years exhibits rich hazelnut-brown colour. It has a very minor crack at the bottom which can be seen on both sides. It doesn't run deep and there's no movement in the slice. Due to the age of petrified wood it's not always possible to polish out every anomaly.
Petrified wood is a type of fossil in which the original organic matter was replaced with natural minerals. The most common tends to be quartz.
The geological process of petrifaction began when prehistoric trees were uprooted during floods. Having fallen they were buried by sediment which starved them of oxygen. This delayed the onset of decay. As a result their original appearance remained largely unchanged.
When decay began to set in any voids were replaced with minerals being carried in groundwater.
The original cell structure often remained intact and acted as a kind of template. This enabled much of the original detail to be retained. As the water dried up the minerals crystallised and hardened.
Petrified forests can be found in a few places around the world one being the Greek island of Lesvos. This ancient forest was covered in volcanic ash around twenty million years ago. One of the best known petrified forests is Petrified Forest National Park in Arizona where the oldest formations date back 227 million years.
This chunky slice of petrified wood has been polished on just one side.
