fossil

Petrified Wood

Silicified wood / Permineralized wood (SiO2)

Hardness of 6.5 to 7 on the Mohs scale, variable colors including brown, yellow, red, and white, vitreous to waxy luster, amorphous crystal structure (quartz/chalcedony replacement), conchoidal fracture, specific gravity around 2.6 to 2.7

Identified August 6, 2026More fossil →

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Physical properties

Formation & geological history

Formed through permineralization, where organic plant material buried in sediment is gradually replaced by minerals (usually silica like quartz or chalcedony) over millions of years

Uses & applications

Used for lapidary work, making ornamental objects, bookends, jewelry, and prized by collectors

Geological facts

Petrified wood preserves the original cellular structure of the ancient trees, sometimes dating back hundreds of millions of years to the Triassic period or earlier

Field identification & locations

Can be identified by its wooden grain textures combined with a stony, heavy feel and glassy hardness; found worldwide in sedimentary rock layers associated with ancient forests and volcanic ash beds

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Fossilized Crinoid Stem in Limestone

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