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 include brown, grey, and tan; vitreous to waxy luster; microcrystalline quartz structure with preserved cellular wood patterns.

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Physical properties

Hardness of 7 on the Mohs scale; colors include brown, grey, and tan; vitreous to waxy luster; microcrystalline quartz structure with preserved cellular wood patterns.

Formation & geological history

Formed when buried organic wood is slowly replaced by silica-rich groundwater over millions of years, typically dating from the Triassic period and onward.

Uses & applications

Used primarily in decorative lapidary items, jewelry, bookends, and sought after by fossil and mineral collectors.

Geological facts

Famous deposits include the Petrified Forest National Park in Arizona, where entire ancient forests transformed completely into stone.

Field identification & locations

Identify by retaining the distinct growth rings and fibrous texture of original wood despite having the heavy weight and glassy hardness of quartz; found globally in sedimentary strata.

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