fossil

Petrified Wood

Silicified wood / Xylopal

AI-generated identification · may be incorrect

Hardness: 6.5 to 7 on the Mohs scale, Color: Brown, tan, red, yellow, and multicolored, Luster: Vitreous to dull, Crystal structure: Microcrystalline quartz (chalcedony/jasper), Specific gravity: 2.5 to 2.7

Hardness: 6

Identified July 29, 2026More fossil →

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Physical properties

Formation & geological history

Formed when organic plant material is buried in an oxygen-depleted environment (such as volcanic ash or sedimentary mud) and groundwater rich in dissolved silica replaces the original cellular structure with minerals over millions of years (typically dating from the Triassic period onwards).

Uses & applications

Used for ornamental carvings, polished display specimens, jewelry, lapidary arts, and as collector items.

Geological facts

Despite looking and feeling like stone, petrified wood preserves the microscopic cellular structure of the original ancient trees, allowing scientists to identify prehistoric plant species.

Field identification & locations

Can be identified by its distinctive wood-like grain and bark texture combined with a cold, heavy stone feel and a hardness that can scratch glass. Found worldwide, with notable deposits in Arizona (Petrified Forest National Park) and Madagascar.