fossil

Petrified Wood

Silicified Wood (SiO2)

Hardness: 6.5-7 Mohs; Color: Brown, tan, red, yellow from iron oxides; Luster: Resinous to waxy; Structure: Preserves original wood grain and cellular structures; Specific Gravity: 2.6-2.9.

Hardness: 6
Color: Brown, tan, red, yellow from iron oxides
Luster: Resinous to waxy

Identified July 13, 2026More fossil →

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Physical properties

Hardness: 6.5-7 Mohs; Color: Brown, tan, red, yellow from iron oxides; Luster: Resinous to waxy; Structure: Preserves original wood grain and cellular structures; Specific Gravity: 2.6-2.9.

Formation & geological history

Formed through permineralization, a process where organic material is replaced by minerals (usually silica/quartz) from groundwater while buried in sediment, typically dating from 20 to 300 million years ago.

Uses & applications

Used for decorative furniture, jewelry cabochons, lapidary art, and as high-demand scientific or museum-grade collectibles.

Geological facts

The colors in petrified wood are caused by trace elements; copper, cobalt, and manganese produce greens and blues, while iron produces reds and yellows.

Field identification & locations

Identify in the field by checking for distinctive tree ring patterns or bark textures on the exterior. Commonly found in areas with historic volcanic activity near ancient riverbeds.