sedimentary

Petrified Wood

Silicified Wood (SiO2)

AI-generated identification · may be incorrect

Hardness: 6.5-7 on Mohs scale; Color: Brown, tan, red, or grey due to mineral impurities like iron and manganese; Luster: Vitreous to waxy; Texture: Preserved wood grain and fibrous cellular structures.

Hardness: 6
Luster: Vitreous to waxy

Identified May 18, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed through the process of permineralization, where organic wood material is replaced by minerals (usually silica) in subterranean sedimentary environments over millions of years, often dating back to the Triassic or Jurassic periods.

Uses & applications

Used primarily for ornamental purposes, jewelry (cabochons), interior design (polished slabs), and as a popular collectable geological specimen.

Geological facts

Famous locations include the Petrified Forest National Park in Arizona. In some specimens, the cell structure is so well-preserved that the original tree species can be identified microscopically.

Field identification & locations

Field identification often relies on seeing wood-like banding or growth rings in a heavy, cold-to-the-touch stone. Commonly found in riverbeds or badlands where erosion exposes ancient sedimentary layers.