Quartz-permineralized fossil wood 34
This is "petrified wood", a terrible term for what is technically called permineralization. Biogenic materials such as wood or bone have a fair amount of small-scale porosity. After burial, the porosity of wood or bone can get partially or completely filled up with minerals as groundwater or diagenetic fluids percolate through. The end result is a harder, denser material that retains the original three-dimensionality (or close to it). The most common permineralization mineral is quartz (SiO2). Sometimes, fossil wood and bone have been permineralized with radioactive minerals such as black uraninite (UO2) or yellowish carnotite (K2(UO2)2(VO4)2·3H2O). Some fossil bones permineralized with cinnabar have been reported (García-Alix et al., 2013, Lethaia 46: 1-6).
Permineralized wood can have microscopic anatomic details preserved, but some fossil wood has no internal structure remaining (in such cases, the fossil preservation style is "replacement" - if quartzose, it's been silicified).
Stratigraphy & locality: unrecorded
Quartz-permineralized fossil wood 34
This is "petrified wood", a terrible term for what is technically called permineralization. Biogenic materials such as wood or bone have a fair amount of small-scale porosity. After burial, the porosity of wood or bone can get partially or completely filled up with minerals as groundwater or diagenetic fluids percolate through. The end result is a harder, denser material that retains the original three-dimensionality (or close to it). The most common permineralization mineral is quartz (SiO2). Sometimes, fossil wood and bone have been permineralized with radioactive minerals such as black uraninite (UO2) or yellowish carnotite (K2(UO2)2(VO4)2·3H2O). Some fossil bones permineralized with cinnabar have been reported (García-Alix et al., 2013, Lethaia 46: 1-6).
Permineralized wood can have microscopic anatomic details preserved, but some fossil wood has no internal structure remaining (in such cases, the fossil preservation style is "replacement" - if quartzose, it's been silicified).
Stratigraphy & locality: unrecorded