2.4" Dendrites On Limestone - Utah
This is a gorgeous 2.4" section of limestone with manganese dendrites on the surface. While they look like plant fossils they are mineral formations, that often occur between layers of sedimentary rock.
Dendrites that occur within rock are most often a result of intruding (percolating) mineral solutions that contained manganese and/or iron. These solutions can work their way through microscopic cracks in the rock, leaving behind a branching pattern throughout the rock. By an untrained eye, these can be mistaken for plant fossils within the rock.