Help identify, rock or bone??

[Russ0369]

I was geode/rock hounding this past weekend in Southern California near the Az border out in the desert and found this. Just curious to know if it's rock or bone and if it is bone should I take it to be looked at. This is unlike any other rock or anything else I've seen out there. 

[fossilized6s]

Welcome. Your find is so dense that I'm not getting a bone vibe. Given the size and shape usually something like this would have whats called a cancelous structure or pattern in the middle. Due to it's almost symmetrical shape on the sides it could be a cast of some sort, but it's doubtful. 

 

Let's see what others say. 

[ynot]

I think it is a broken iron concretion .

[Plax]

let's have some close ups of the ends please.

[Spinosaurus]

i think its bone, but i dont know why 

[Russ0369]

I'll take some close up pics of the ends when I get home in a few hours.  If it is just a rock what would cause the round cylindrcal shape it has when here is no other rocks in the area that is even remotely similar?