Rock Identifier
Petrified wood (Silicified fossil wood; commonly quartz (SiO₂) replacing wood tissue) — fossil
fossil

Petrified wood

Silicified fossil wood; commonly quartz (SiO₂) replacing wood tissue

AI-generated identification · may be incorrect

Tan to gray-brown, woody grain and growth-ring-like bands; typically hardness about 6.5–7, vitreous to dull luster, and no cleavage. The pictured piece appears weathered and partly wood-textured; identification from an image is not definitive.

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Physical properties

Tan to gray-brown, woody grain and growth-ring-like bands; typically hardness about 6.5–7, vitreous to dull luster, and no cleavage. The pictured piece appears weathered and partly wood-textured; identification from an image is not definitive.

Formation & geological history

Forms when buried wood is gradually replaced by silica-rich groundwater while preserving its structure, often in volcanic or sedimentary deposits. Fossilization spans many geological ages, commonly from the late Paleozoic through the Cenozoic.

Uses & applications

Polished pieces are used for ornaments, jewelry, and collectibles; larger pieces may be decorative stone.

Geological facts

Silica can preserve fine details of the original wood, including cells and growth rings.

Field identification & locations

Look for wood grain or rings with a stone-like weight and hardness; common deposits include Arizona, Madagascar, and Indonesia. This specimen’s visible fibrous texture makes field confirmation useful.

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