Hello together,
I got this one as a gift, all the info I have is "rock with a nice pattern from the Sahara desert ".
I am relatively sure its not a fossil, even more so after looking at the macro-fotos.
Still it reminded me of tentaculites, and I wonder if there are fossils disguised by desert varnish, or if it is all pure geology.
What do you think?
Scale is metric, as you can tell by the ten/five small marks to a big one.
Best regards,
J