fossil

Petrified Wood

Silicified wood (primarily Quartz, SiO2)

Hardness: 7 on the Mohs scale; Colors vary widely including white, green, brown, red, and yellow due to mineral impurities; Luster: Vitreous to dull; Crystal structure: Microcrystalline quartz (chalcedony/jasper); Specific gravity: 2.5 to 2.8

Hardness: 7 on the Mohs scale
Luster: Vitreous to dull

Identified July 28, 2026More fossil →

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Physical properties

Formation & geological history

Formed millions of years ago when plant material was buried in sediment under anoxic conditions and saturated with mineral-rich water, slowly replacing organic matter with silica over geologic time.

Uses & applications

Used in decorative items, lapidary arts, jewelry, bookends, and collected by rockhounds and fossil enthusiasts.

Geological facts

Petrified wood can preserve intricate cellular structures of ancient trees, allowing scientists to study prehistoric ecosystems and climate change dating back hundreds of millions of years.

Field identification & locations

Can be identified in the field by its distinct wood-like grain and texture combined with a heavy, rock-like weight and glassy fracture. Commonly found in areas with ancient volcanic activity and sedimentary basins.

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