sedimentary
Petrified Wood
Silicified Wood (SiO2)
Hardness: 6.5-7 on Mohs scale; Color: Brown, tan, red, or grey due to mineral impurities like iron and manganese; Luster: Vitreous to waxy; Texture: Preserved wood grain and fibrous cellular structures.
- Hardness
- 6
- Luster
- Vitreous to waxy
Identified More sedimentary →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6.5-7 on Mohs scale; Color: Brown, tan, red, or grey due to mineral impurities like iron and manganese; Luster: Vitreous to waxy; Texture: Preserved wood grain and fibrous cellular structures.
Formation & geological history
Formed through the process of permineralization, where organic wood material is replaced by minerals (usually silica) in subterranean sedimentary environments over millions of years, often dating back to the Triassic or Jurassic periods.
Uses & applications
Used primarily for ornamental purposes, jewelry (cabochons), interior design (polished slabs), and as a popular collectable geological specimen.
Geological facts
Famous locations include the Petrified Forest National Park in Arizona. In some specimens, the cell structure is so well-preserved that the original tree species can be identified microscopically.
Field identification & locations
Field identification often relies on seeing wood-like banding or growth rings in a heavy, cold-to-the-touch stone. Commonly found in riverbeds or badlands where erosion exposes ancient sedimentary layers.
More like this
Other sedimentary specimens
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary
Shale or Slaty Mudstone
Argillaceous sedimentary rock
sedimentary
Chert Breccia
Brecciated Chert (Microcrystalline Silica)
sedimentary
Sandstone (Quartz-rich)
Arenite (SiO2)
sedimentary
Sandstone (with man-made markings)
Arenite (composed primarily of Quartz, SiO2)
sedimentary