The Bonsai and Penjing Collection has an ancient 165 million year old petrified tree stump on display, kindly donated by The National Dinosaur Museum. The petrified stump is a rare fossil dating back to the Jurassic era and came from the Wandoan region in Queensland. Petrified comes from the Greek root 'petro' meaning "rock" or "stone"; literally "wood turned into stone".
Petrified wood forms when trees or plants fall and are buried by sediment in an environment free of oxygen. This initially preserves the original plant structure and general appearance. Then, mineral-laden water flows through the tissues, replacing the organic plant structure with inorganic minerals such as quartz or calcite, pyrite or another inorganic material such as opal.
The end result is petrified wood, a plant with its original basic structure intact, but replaced by stone.