fossil

Petrified wood

Silicified wood; commonly quartz (SiO₂) replacing wood tissue

AI-generated identification · may be incorrect

Typically hardness 6.5–7, opaque, with reddish-brown, cream, and gray bands preserving wood grain; vitreous to dull luster and no true cleavage. The specimen appears polished or naturally smoothed, with a dense, finely crystalline quartz structure.

Identified August 16, 2026More fossil →

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Physical properties

Formation & geological history

Buried wood was gradually replaced by silica-rich groundwater during diagenesis, preserving cellular structure and growth rings; individual pieces may range from Paleozoic to Cenozoic age. Commonly forms in volcanic ash-bearing sediments and floodplain deposits.

Uses & applications

Used as a lapidary material for cabochons, carvings, bookends, and decorative slabs; it is also popular with fossil and mineral collectors.

Geological facts

Iron oxides commonly create the red and brown coloration, while manganese or other impurities produce darker tones. Wood grain and cellular patterns remain visible despite complete mineral replacement.

Field identification & locations

Identify it by recognizable bark, grain, knots, or growth-ring patterns combined with stone-like weight and hardness; it will not feel fibrous or woodlike. Common sources include Arizona, Utah, Madagascar, Indonesia, and Australia.