fossil

Petrified Wood

Silicified Wood (SiO2)

Hardness: 6.5-7 on Mohs scale. Color: Tan, beige, light brown. Luster: Dull to waxy. Structure: Retains visual appearance of original xylem or wood grain. Specific gravity: 2.6-2.9.

Hardness: 6
Color: Tan, beige, light brown
Luster: Dull to waxy

Identified July 10, 2026More fossil →

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Physical properties

Hardness: 6.5-7 on Mohs scale. Color: Tan, beige, light brown. Luster: Dull to waxy. Structure: Retains visual appearance of original xylem or wood grain. Specific gravity: 2.6-2.9.

Formation & geological history

Formed via permineralization when woody plants are buried in sediment and organic tissue is replaced by minerals, typically silica from volcanic ash, over millions of years (often Mesozoic or Cenozoic).

Uses & applications

Commonly used for geological collections, jewelry (cabochons), interior decor, and scientific study of paleobotany.

Geological facts

The process can preserve the cellular structure of the original plant so perfectly it can be identified under a microscope. Entire petrified forests exist, such as in Arizona, USA.

Field identification & locations

Identified by wood-like texture, grain, and growth rings in a heavy, stone-hard specimen. Commonly found in areas with past volcanic activity and sedimentary wash.