fossil

Petrified Wood

Silicified wood (Quartz/Chalcedony replacement of cellulose)

Hardness: 6.5 - 7 (Mohs); Color: Brown, grey, tan, and reddish hues; Luster: Vitreous to waxy; Structure: Retains cellular structure of original wood; Cleavage: None

Hardness: 6
Color: Brown, grey, tan, and reddish hues
Luster: Vitreous to waxy

Identified July 6, 2026More fossil →

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Physical properties

Hardness: 6.5 - 7 (Mohs); Color: Brown, grey, tan, and reddish hues; Luster: Vitreous to waxy; Structure: Retains cellular structure of original wood; Cleavage: None

Formation & geological history

Formed through permineralization over millions of years (commonly Carboniferous to Cenozoic), where organic wood remains are replaced by silica (Quartz) carried in groundwater within anaerobic sedimentary environments.

Uses & applications

Polished for lapidary use, jewelry, decorative ornaments, and highly valued as educational and museum-quality fossil specimens.

Geological facts

The most famous location is the Petrified Forest National Park in Arizona. It can preserve even the smallest microscopic details of the original tree bark and rings.

Field identification & locations

Look for a heavy, stone-like weight combined with visible wood grain, tree rings, or bark textures. Commonly found in eroded sedimentary badlands or riverbeds near volcanic ash deposits.

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