What did I find?

[Debbie]

Found this in a creek bed in North Mississippi- any ideas on what it is??

[willjo]

Not sure what size that is but a friend of mine sent me some rocks similar to that, they were quarter size. I polished them in my rock tumbler and they looked similar to that. They were agates

[Debbie]

It's as large as my hand

[sailorjoe]

It looks like a fossil coral to me. And I am not in any way knowledgeable about fossils. But it looks like what some folks call a "brain coral".

[Lindenmeier-Man]

Of all the things I’ve lost in my life, I miss my mind the most ! So you found my brain ? Not a geologist but I’m thinking fossil coral , like Joe above. If it is, it’s very collectible ! JJ

[redrocks]

Maybe a fossilized sponge