Reddish-multi-colored petrified conifer, wood slice from Arizona, Araucaria

A polished slice of petrified conifer wood, recovered from deposits in Arizona. The original wood comes from the Triassic genus Araucaria, whose trunks were petrified in volcanic ash approximately 220 million years ago.

Petrified wood is formed by permineralization. Groundwater containing silica penetrates the cellular structures of the wood, replacing the organic material cell by cell with quartz or chalcedony. The wood fiber structure is preserved and is still visible today in cross-section.

The reddish-brown color bands are created by incorporated iron oxides during mineralization. Various iron oxidation states produce the characteristic spectrum from pale pink to deep red.

The deposit in the Petrified Forest National Park, Arizona, is one of the oldest and richest in the world. Today, mining is prohibited within the park area; well-preserved material comes from historical collections or private lands on the park's borders.

A paleontological collector's item with clear geological provenance.