fossil

Petrified Wood

Silicified Wood (SiO2)

Hardness: 6.5 - 7 on Mohs scale. Color: Shades of brown, reddish-brown, yellow, gray, and black. Luster: Vitreous to dull. Texture: Fibrous wood grain structure preserved in chalcedony/quartz.

Hardness: 6
Color: Shades of brown, reddish-brown, yellow, gray, and black
Luster: Vitreous to dull

Identified July 26, 2026More fossil →

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Physical properties

Hardness: 6.5 - 7 on Mohs scale. Color: Shades of brown, reddish-brown, yellow, gray, and black. Luster: Vitreous to dull. Texture: Fibrous wood grain structure preserved in chalcedony/quartz.

Formation & geological history

Forms when plant material is buried by sediment and protected from decay due to oxygen deficiency. Mineral-laden groundwater flowing through the sediment deposits minerals in the plant's cells, replacing organic matter over millions of years.

Uses & applications

Used widely for lapidary work, decorative display pieces, carved bookends, jewelry, and educational rock collection sets.

Geological facts

Petrified wood can retain cellular details of the original tree, allowing paleobotanists to identify the species of tree that lived tens to hundreds of millions of years ago.

Field identification & locations

Look for distinct organic cellular textures, growth rings, and bark-like exterior textures that show the hardness and weight of quartz mineral replacement. Found in fossilized forests, sedimentary deposits, and gravel beds worldwide.