Rock Identifier
Petrified Wood (Silicified Wood (SiO2)) — fossil
fossil

Petrified Wood

Silicified Wood (SiO2)

AI-generated identification · may be incorrect

Hardness of 7 on the Mohs scale. Colors vary from brown and gray to red and yellow, featuring a vitreous to waxy luster and cryptocrystalline quartz structure.

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Physical properties

Hardness of 7 on the Mohs scale. Colors vary from brown and gray to red and yellow, featuring a vitreous to waxy luster and cryptocrystalline quartz structure.

Formation & geological history

Formed over millions of years when buried organic wood is slowly replaced by silica-rich groundwater under anaerobic conditions.

Uses & applications

Used widely in decorative carvings, lapidary arts, high-end jewelry, and as collectible display specimens.

Geological facts

Famous occurrences include the Petrified Forest National Park in Arizona, featuring specimens dating back over 200 million years to the Triassic period.

Field identification & locations

Identified by retaining the original cellular wood grain structure while exhibiting the high hardness and conchoidal fracture of quartz. Found globally in sedimentary strata.

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