fossil

Fossilized wood fragment

Petrified wood; commonly silicified fossil wood (SiO₂ replacing organic tissue)

AI-generated identification · may be incorrect

Brown to gray, elongated woody texture with preserved grain and porous cellular structure; typically hardness 6.5–7, vitreous to dull luster, no cleavage, and specific gravity about 2.2–2.7. The specimen appears partly mineralized rather than a fully polished piece.

Identified August 10, 2026More fossil →

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Physical properties

Formation & geological history

Forms when buried wood is protected from decay and groundwater replaces its tissues with silica, calcite, or other minerals while preserving cellular detail. Petrified wood ranges from Paleozoic to Cenozoic in age, commonly tens of millions of years old.

Uses & applications

Used as a lapidary material for cabochons, carvings, bookends, and decorative specimens; finely patterned material is collectible.

Geological facts

Silicified wood may retain growth rings, bark, and microscopic cell structure despite being stone. Iron, manganese, and other trace elements create brown, red, yellow, or black colors.

Field identification & locations

Identify by visible wood grain or cellular patterns, stone-like weight, and inability to bend or splinter; a steel file generally will not scratch silica-rich material. Common localities include Arizona, Oregon, Indonesia, Madagascar, and Australia.