Rock?

[Jeffg]

Found this guy on a train track. Looks like possibly a fossil. There is a round hole on the top where you can see a layer of what appears to be a thin layer of bone and in the center red crystalline matter. Any help would be appreciated.

[Rockwood]

This is going to be a hard one to visualize, but I'm reasonably sure that it's a mold fossil of a crinoid stem. 

[Fossildude19]

An orthocone cephalopod would better explain the tapering at one end.

 

 

The size of this item would be helpful to know.

[Rockwood]

6 minutes ago, Fossildude19 said:

An orthocone cephalopod would better explain the tapering at one end.

There are what appear to be crenulae in the lower right. The inner features look more like lumen cast than a siphuncle as well. I think the taper is an illusion caused by the angle of the section. 

[Fossildude19]

7 minutes ago, Rockwood said:

There are what appear to be crenulae in the lower right. The inner features look more like lumen cast than a siphuncle as well. I think the taper is an illusion caused by the angle of the section. 

 

Possible.    

Not sure those are actually crenulae.

Pictures aren't detailed enough for me to say for sure, one way, or the other.

 

Better pictures, including pictures of the ends of the item, and measurements/size might help.

[Ludwigia]

If the OP would at least give info on the provenance, it would perhaps be easier to determine what this might be.