<Table> <Tr> <Td> </Td> <Td> This article needs additional citations for verification . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . (November 2008) (Learn how and when to remove this template message) </Td> </Tr> </Table> <Tr> <Td> </Td> <Td> This article needs additional citations for verification . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . (November 2008) (Learn how and when to remove this template message) </Td> </Tr> <P> Petrified wood (from the Greek root petro meaning "rock" or "stone"; literally "wood turned into stone") is the name given to a special type of fossilized remains of terrestrial vegetation . It is the result of a tree or tree - like plants having completely transitioned to stone by the process of permineralization . All the organic materials have been replaced with minerals (mostly a silicate, such as quartz), while retaining the original structure of the stem tissue . Unlike other types of fossils which are typically impressions or compressions, petrified wood is a three - dimensional representation of the original organic material . The petrifaction process occurs underground, when wood becomes buried under sediment or volcanic ash and is initially preserved due to a lack of oxygen which inhibits aerobic decomposition . Mineral - laden water flowing through the covering material deposits minerals in the plant's cells; as the plant's lignin and cellulose decay, a stone mold forms in its place . The organic matter needs to become petrified before it decomposes completely . A forest where such material has petrified becomes known as a petrified forest . </P> <P> Elements such as manganese, iron, and copper in the water / mud during the petrification process give petrified wood a variety of color ranges . Pure quartz crystals are colorless, but when contaminants are added to the process the crystals take on a yellow, red, or another tint . </P>

Petrified wood is an example of what type of fossil