So, I was out one day around my house and came acrossed this, and at first glance I didnt think it was anything, but got to thinking about it more and more seeing all these artifacts on here and I was like, man this rock could be an artifact. I was thinking its a sea sponge of some sort, possibly carried all the way to missouri by the mermaids? What do you think? Could it be something else? Is it valuable?