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, earthy to vitreous luster, multicolored hues of brown, red, and yellow, with preserved cellular wood structure.

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Physical properties

Hardness of 7 on the Mohs scale, earthy to vitreous luster, multicolored hues of brown, red, and yellow, with preserved cellular wood structure.

Formation & geological history

Formed over millions of years when buried organic wood is slowly replaced by silica-rich groundwater in anoxic sedimentary environments.

Uses & applications

Used primarily for ornamental decorative objects, lapidary art, high-end jewelry, and as a popular specimen for fossil collectors.

Geological facts

Famous occurrences include the Petrified Forest National Park in Arizona, where entire ancient Triassic trees have been completely replaced by quartz.

Field identification & locations

Identified by retaining distinct growth rings and bark texture combined with a glass-like hardness that cannot be scratched by steel.

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