fossil

Petrified wood (likely silicified wood)

Silicified xylem, composed mainly of microcrystalline quartz (SiO₂)

AI-generated identification · may be incorrect

Hardness about 6.5–7 Mohs; brown, tan, and gray coloration with preserved grain or cellular pattern; dull to waxy luster, generally non-cleavable, and dense. The cut face appears polished or naturally smoothed.

Identified August 22, 2026More fossil →

Explore Petrified wood (likely silicified wood) in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Formation & geological history

Buried wood was permineralized as silica-rich groundwater replaced or filled its cells, preserving the texture; ages range widely, commonly tens to hundreds of millions of years. It forms in volcanic-ash-rich sediments, floodplains, and groundwater environments.

Uses & applications

Used as a lapidary material for cabochons, bookends, carvings, and display specimens; not typically used structurally. Value depends on pattern, polish, size, locality, and degree of silicification.

Geological facts

The visible mottling and wood-grain-like structure strongly support petrified wood, though the image alone cannot confirm species or locality.

Field identification & locations

Identify by recognizable cellular or growth-ring patterns, high density, quartz-like hardness, and inability to scratch with a steel knife; common sources include Arizona, Utah, Madagascar, Indonesia, and Australia.