sedimentary

Petrified Wood

Silicified Wood (primarily SiO2)

Hardness: 6.5-7 (Mohs). Color: White, cream, tan with yellow/brown iron staining. Luster: Vitreous to waxy. Structure: Preservation of original cellular or bark textures. Cleavage: None (conchoidal fracture).

Hardness: 6
Color: White, cream, tan with yellow/brown iron staining
Luster: Vitreous to waxy

Identified June 24, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed through permineralization, a process where organic material is replaced by silica (usually quartz or chalcedony) from groundwater over millions of years. This process occurred most frequently during the Mesozoic and Cenozoic eras.

Uses & applications

Used for lapidary work, decorative landscaping, jewelry (cabochons), and as a popular geological collectible. High-quality specimens are used for museum-grade displays.

Geological facts

The specimen shows a clear curved impression characteristic of a tree trunk or branch circumference. The Trans-Mexican Volcanic Belt (near the 19.2°N, 99.5°W region) contains many areas where volcanic ash buried forests, facilitating petrification.

Field identification & locations

Identify by looking for wood-like grain, growth rings, or bark textures in a material that feels like stone and cannot be scratched by a steel knife. Common in volcanic sedimentary basins throughout central Mexico.