Fossil?

[Karam]

Hello! Found yesterday, although I'm not even sure what it is. I put rudists in the tag section since someone told me if you don't know what it is, then it's probably a rudist (especially in Lebanon). I would also like to mention that those patterns are not only on one side, rather they're everywhere even on the small pieces that fell off while i separated it from a bigger rock. 

Edited March 12, 2021 by Karam
Adding picture

[FranzBernhard]

3 hours ago, Karam said:

rudist

Hard to say! Is it 3D? Can you see some structure in the "shell", eg. plates, lamellae, cellular structure?

Franz Bernhard

[Mahnmut]

Maybe something like a stromatolith?

Best Regards,

J

[Karam]

4 hours ago, FranzBernhard said:

Hard to say! Is it 3D? Can you see some structure in the "shell", eg. plates, lamellae, cellular structure?

Franz Bernhard

Hello Franz! Thank you for your reply, first of all I'll start by saying it is 3D. They look like leaves on top of one another that goes all around the rock (standing vertically) they pretty much branch out throughout the whole rock. Now concerning lamellae, there is no purtruding cellular structure however, as shown below, there is a thick outline at the end of each "leaf" 

 

In addition the rock shows the same pattern from the back, and the top (transverse or axial view)

Below is a picture  of the back of the rock 

 

P.S it has small pieces of broken shell in some places in the rock, however I see this on almost every rock I observe. 

 

Some additional pics

[Karam]

15 minutes ago, Mahnmut said:

Maybe something like a stromatolith?

Best Regards,

J

Hello thank you for your reply! At first I was skeptical it was just formation (still am), however the patterns are removable. They are In a much weaker kind of rock when compared to the rock itself. Once I removed one of the patterns, the rock below is clear. Not sure if this can happen and still be a kind of rock formation! 

 

Update: I searched some pictures of stromatolites and they seem very close to this. Could this be it? However mine is very fragile and the layers can be easily removed, does this still count as a stromatolite? Thank for the Input! 

Edited March 12, 2021 by Karam
Update

[Mahnmut]

Well, that makes it less  plausible to be a fossil. could be mineral staining. Water containing dissolved iron minerals, chemically similar to rust, could have entered a fissure in the rock and left the pattern you see when evaporating. These are often looking similar to fossils. If it was a fossil (rudist, coral, stromatolith) there should be a 3d structure.

Still an interesting piece.

Best Regards,

J

[Karam]

5 minutes ago, Mahnmut said:

Well, that makes it less  plausible to be a fossil. could be mineral staining. Water containing dissolved iron minerals, chemically similar to rust, could have entered a fissure in the rock and left the pattern you see when evaporating. These are often looking similar to fossils. If it was a fossil (rudist, coral, stromatolith) there should be a 3d structure.

Still an interesting piece.

Best Regards,

J

Now oddly it is 3d and it goes all over inside the rock. This was a larger rock that I broke, on the outside of the rock was the same pattern on the inside (piece that I have). Anyway I will do some more observing for clues next time I pass by the same site I got it in. 

Thank you so much!

[FranzBernhard]

I am now also in the mineral staining camp. However, the staining seems to be controlled by some "structural elements". There is more than staining to it, but I have no clue. Does not look like burrows etc. 

Franz Bernhard

[TqB]

I agree it looks like mineral staining, a version of Liesegang rings.