Help with ID please.

[$Lynn$]

So my grandson and I were collecting rocks from my land in N.E. Oklahoma around chelsea okla. I found these elongated rocks with what looks like a rock growth on them. they are brittle I dropped one and it broke with ease. You can see in pic the center of the broken one. If you tap them together while loading they sound metallic ish. they are seemingly heavy. smooth but in places looks like a growth. The growth is as hard as rock itself. Thanks ahead for your help. the first pic is the broken one. its mate is in the forground.

[bigrex]

Looks potentially sedimentary, not sure of much else.

[Morlock]

Limestone perhaps? Put a few drops of warm vinegar on it. If it fizzes after a few minutes, it's limestone.

[4meter]

I agree with Morlock.  Looks like a fossiliferous limestone that is  weathering unevenly due to different difference in the material that makes up the rock.

[$Lynn$]

Thanks gentlemen. i will do it and report back. o did find fossils in it as well...shells and creatures.

[chrisski]

Are they typical of the rocks found in that area?  To me it kind of looks like what someone may have used as an old cobble sidewalk.  If there's lots of those spread all over, I doubt it, if they were found in one group, maybe.