Thank you for your considered answer. Grazzi!
However, I did some more "googeling" and found the following explanation:
http://en.wikipedia.org/wiki/Dendrite_(crystal)
Mineralogy and palaeontology
In palaeontology, dendritic mineral crystal forms are often mistaken for fossils. These pseudo fossils form as naturally occurring fissures in the rock are filled by percolating mineral solutions. They form when water rich in manganese and iron flows along fractures and bedding planes between layers of limestone and other rock types, depositing dendritic crystals as the solution flows through. A variety of manganese oxides and hydroxides are involved, including:
birnessite (Na4Mn14O27•9H2O)
coronadite (PbMn8O16)
cryptomelane (KMn8O16)
hollandite (BaMn8O16)
romanechite ((Ba,H2O)Mn5O10)
todorokite ((Ba,Mn,Mg,Ca,K,Na)2Mn3O12•3H2O) and others.
A three-dimensional form of dendrite develops in fissures in quartz, forming moss agate.
In addition, I found here:
http://woostergeologists.scotblogs.woos ... e-germany/
How can you tell this is not a fossil plant? For one, the branches are too perfect: none overlap or are folded over or broken, as you would expect in a buried three-dimensional plant. Next, you will notice that all the branches extend from a line at the bottom of the image rather than from a single branching point. Finally, there is no distinction between branch, stem or leaf; instead, it is a fractal-like Distribution of tiny sharp-edged crystals.
Tislijiet minn Mandelbrot
Sigra
! Grazzi !
