Brazilian Petrified Tree Fern Wood
Species: Psaronius brasiliensis
Location: Bieland, Maranhao Province, Brazil
Pedra de Fogo Formation
Petrified wood (from the Greek root petro meaning “rock” or “stone”; literally “wood turned into stone”) the name given to a particular type of fossilized remains of terrestrial vegetation. It is the result of a tree or tree-like plants wholly 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. Elements such as manganese, iron, and copper in the water/mud during the petrification process give petrified wood a variety of color ranges.
This is a slice of petrified wood identified as Psaronius
brasiliensis and measures 7.75” x 7”.