mineral
Petrified Wood
Silicified Wood (SiO2)
Hardness: 6.5-7 (Mohs scale); Color: Brown, grey, tan, cream; Luster: Vitreous to waxy; Crystal structure: Amorphous or cryptocrystalline (Chalcedony/Quartz); Cleavage: None; Specific gravity: 2.6-2.9
- Hardness
- 6
- Color
- Brown, grey, tan, cream
- Luster
- Vitreous to waxy
Identified More mineral →
Explore Petrified Wood in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6.5-7 (Mohs scale); Color: Brown, grey, tan, cream; Luster: Vitreous to waxy; Crystal structure: Amorphous or cryptocrystalline (Chalcedony/Quartz); Cleavage: None; Specific gravity: 2.6-2.9
Formation & geological history
Formed through permineralization where organic wood materials are replaced by minerals (usually silica) in anaerobic conditions over millions of years, often by volcanic ash or waterborne sediments.
Uses & applications
Used for ornamental carvings, jewelry (lapidary), furniture (tabletops), and highly valued as geological display specimens.
Geological facts
Petrified wood is a fossil in which the organic remains have been replaced by minerals in the slow process of being turned into stone over a period of many millions of years.
Field identification & locations
Identify by tree-like growth rings, bark-like texture, and superior hardness compared to standard wood. Commonly found in Arizona (USA), Madagascar, and Indonesia.
More like this
Other mineral specimens
Sandstone (with potential mineral staining/concretions)
Arenite (SiO2 based)
sedimentary
Schist
Schist
Metamorphic
Epidote
Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)
metamorphic
Gypsum (variety Selenite or Alabaster)
Calcium sulfate dihydrate (CaSO4·2H2O)
Mineral
Nephrite Jade
Nephrite
Mineral/Rock
Banded Gneiss (River Rock/Pebble)
Gneiss (specifically a banded variety often found as a river rock)
Metamorphic Rock