strange find

[Goldmantle]

Today I was out playing in a local stream, and I found some unusual rocks, I have no idea what the are, maybe someone here can help me, I'll post some pictures



You will notice the metallic line running threw it, I have several like this.
And I he this other stone , it's a little harder to see, but you will notice the entire core it metallic colored, the stones all take a magnet.
Prolly not worth anything, but I need to learn what I'm looking at.



Any help would be great.

 

[Goldmantle]

I dug some of the chucks out of the rocks, it def has a metallic shean to it, and the black material around is is magnetic.
#befuddled