mineral

Petrified Wood

Silicified Wood (primarily SiO2)

Hardness (Mohs): 6.5-7.0. Color: Varieties of red, brown, tan, and grey. Luster: Vitreous to dull. Structure: Preservation of original cellular woody texture. Cleavage: None (conchoidal fracture). Specific Gravity: 2.6-2.9.

Color: Varieties of red, brown, tan, and grey
Luster: Vitreous to dull

Identified May 28, 2026More mineral →

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Physical properties

Formation & geological history

Formed through permineralization, where organic remains are replaced by minerals (usually silica) from groundwater while buried under sediment or volcanic ash. This specimen likely dates from the Triassic to Eocene periods.

Uses & applications

Used primarily for ornamental purposes, jewelry (cabochons), interior design (tables, bookends), and as a popular collector's item.

Geological facts

Petrified wood is the state gemstone of Washington and the state fossil of Arizona. The famous Petrified Forest National Park contains wood that is over 200 million years old.

Field identification & locations

Identify by looking for bark-like textures or growth rings on the exterior and a glassy, stone-like interior. Commonly found in areas with past volcanic activity and sedimentary basins like Arizona, Oregon, and Madagascar.