Red-variegated petrified conifer, wood slice from Arizona, Araucaria

A ground and polished wood slice of petrified conifer wood, recovered from the classic deposits in Arizona. The original wood comes from the Triassic genus Araucaria. The trunks were encased in volcanic ash about 220 million years ago and transformed into colorful stone through mineralization processes.

Petrified wood is formed by permineralization. Silicic groundwater penetrates the cell structures of the wood and replaces the organic material cell by cell with quartz, chalcedony, or opal. The wood fiber structure is preserved and is now visible as a cross-section.

The reddish-brown colorations are caused by embedded iron oxides. These were washed into the wood pores from the surrounding sediments during mineralization. Different iron oxidation states create the spectrum from light pink to deep red.

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

A paleontological collector's item with a clear geological narrative and aesthetically diverse coloration.