fossil

Petrified Wood

Silicified wood (Quartz replacement, SiO2)

Hardness: 6.5-7 on the Mohs scale, Color: Brown, yellow, grey, and tan with distinct longitudinal grain patterns, Luster: Vitreous to dull, Crystal structure: Microcrystalline quartz (chalcedony/jasper)

Hardness: 6

Identified August 4, 2026More fossil →

Explore Petrified Wood in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Formation & geological history

Formed when buried organic plant material is saturated with mineral-rich water, allowing silica to replace organic matter cell-by-cell over millions of years

Uses & applications

Used in lapidary arts, decorative items, bookends, jewelry, and prized by fossil and mineral collectors

Geological facts

The wood structure, including growth rings and cellular details, is often perfectly preserved in stone

Field identification & locations

Identified by its wood-like grain and texture combined with a stone-like weight and hardness of quartz; commonly found in ancient alluvial deposits and volcanic ash beds worldwide

Other fossil specimens

See all

Crinoid Stem Fossil in Matrix

Phylum Echinodermata, Class Crinoidea

fossil

Sedimentary Outcrop (Sandstone/Shale)

Sedimentary bedrock formation (variable composition)

sedimentary

Chert with Fossil Brachiopod

Microcrystalline Quartz (SiO2) with Calcitic Brachiopod inclusion

sedimentary

Crinoid Stem Fossils (Indian Beads / St. Cuthbert's Beads)

Crinoid columnal ossicles (phylum Echinodermata)

fossil

Fossilized Crinoid Stem in Limestone

Crinoidea (Class) in Calcium Carbonate (CaCO3) matrix

fossil

Fossiliferous Limestone

Limestone with embedded fossil cross-section

sedimentary