| MadSci Network: Environment/Ecology |
The formation of petrified wood takes millions of years and involves a process known as silicification in which silica dissolved in groundwater replaces the organic material in fallen tree trunks and branches. Other environmental factors such as temperature and pressure over time play an important role in converting the silicized wood into chert(quartz). The presence of inorganic compounds such as manganese, copper and iron oxides will affect the color of the petrified wood, often producing spectacular rainbows of colors as seen in many specimens from the Petrified National Forest in the southwestern US.