A permineralized piece of wood

A per mineralized piece of wood is known as the "petrified wood."

Explanation:

The petrified wood are available in few parts of the world with variety of colors, which happens as a result of presence trace elements inside the mineral by which the petrified wood is made. It is also believed that they are the remaining of the fossils of terrestrial vegetation. It is made from tree or some tree like plants which have been undergone mineralization process. These woods are much heavier than the normal one.