Rock Identifier
Petrified wood (Silicified fossil wood, commonly preserved as microcrystalline quartz (SiO₂)) — fossil
fossil

Petrified wood

Silicified fossil wood, commonly preserved as microcrystalline quartz (SiO₂)

AI-generated identification · may be incorrect

Opaque, mottled reddish-brown, gray, and cream; quartz-rich material has Mohs hardness about 6.5–7 and a waxy to dull luster. The rounded, weathered surface obscures any visible wood grain; crystal structure is typically microcrystalline quartz.

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Physical properties

Opaque, mottled reddish-brown, gray, and cream; quartz-rich material has Mohs hardness about 6.5–7 and a waxy to dull luster. The rounded, weathered surface obscures any visible wood grain; crystal structure is typically microcrystalline quartz.

Formation & geological history

Buried wood can be mineralized as silica-rich groundwater replaces or fills its tissues, preserving the wood’s structure. Petrified wood occurs in sedimentary deposits of many ages, from the Permian to recent geological periods.

Uses & applications

Used for lapidary carvings, polished specimens, and decorative objects; silicified wood is generally too irregular for construction use.

Geological facts

Some specimens preserve growth rings and cellular details despite being stone.

Field identification & locations

Look for wood grain, growth rings, or cellular patterns and a stone-like hardness; common deposits include the western United States. This image alone does not show diagnostic grain clearly, so identification is tentative.

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