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

Petrified Wood

Silicified wood (principally SiO2)

AI-generated identification · may be incorrect

Hardness 6.5–7 on the Mohs scale, earthy to waxy luster, microcrystalline quartz structure, typically showing brown, tan, and dark gray growth rings or fibrous wood texture.

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Physical properties

Hardness 6.5–7 on the Mohs scale, earthy to waxy luster, microcrystalline quartz structure, typically showing brown, tan, and dark gray growth rings or fibrous wood texture.

Formation & geological history

Formed when organic plant material is buried under sediment or volcanic ash, allowing silica-rich groundwater to permineralize cellular structures over millions of years.

Uses & applications

Commonly used in lapidary arts, jewelry, decorative carvings, bookends, and sought after by fossil collectors.

Geological facts

Permineralization can preserve cellular structures so finely that individual tree rings and microscopic bark structures remain visible.

Field identification & locations

Identify in the field by checking for wood-grain patterns combined with mineral-like heaviness and high hardness that scratches glass; common in volcanic sedimentary basins.

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