Petrified wood
Fossil
Also called Fossil wood, Silicified wood, Agatized wood, and Opalized wood
About it
Wood turned to stone, mostly chalcedony or opal, often keeping its rings and bark. Arizona, Madagascar, and Indonesia are big sources; taking it from Petrified Forest National Park is illegal, but small personal amounts are allowed on US BLM land.
- Type
- Fossil (plant)
- Group
- Wood (plant)
- Hardness (Mohs)
- 6.5–7
- Lustre
- vitreous (glassy), waxy, dull
- Colours
- brown, red, yellow, grey, black, white, multicoloured
- Transparency
- translucent, opaque
- Cleavage and fracture
- none; conchoidal to splintery fracture
- Periods
- Permian, Triassic, Jurassic, Cretaceous, Paleogene, Neogene
Typical values: real specimens vary. For more, see mindat.org.