large, solid petrified tree trunk, (not a slice) conifer from Arizona, Araucaria

A massive petrified log from Arizona, not merely a cross-section but an elongated piece of a complete Triassic-era Araucaria trunk in gallery format. The original wood fiber structure is preserved through permineralization in multicolored quartz.

Petrified wood from the Petrified Forest National Park in Arizona is approximately 220 million years old. The trunks of the Araucaria genus lay in volcanic ash, into which silica-rich groundwater infiltrated, replacing the organic material cell by cell with quartz, chalcedony, or opal.

The reddish-brown, yellow, and black color bands are created by traces of iron, manganese, and carbon in varying concentrations. Each color layer represents local mineralization conditions during the petrification process.

A continuous piece of trunk of this length is significant for collectors: most finds are smaller fragments or thin slices. The park area does not allow retrieval today; well-preserved material comes from historical collections or neighboring private lands.

The Araucaria genus still includes living relatives in South America and Australia. The Triassic-era species were widespread regionally, and the Petrified Forest material documents this ancient distribution as a petrified trunk archive.