Is this Native American ?

[Chainshot]

I went metal detecting for Civil War, stuff today. I've been doing it for about 20 years. The detector got a signal and I started digging. Found just a chunk of old iron. But....while digging, my eye spotted this thing. It was about 1ft. down.

It is VERY smooth to the touch and about the size of a quarter. Appears natural to me and not man made ? Dug not too far from a river. Also lots of Indian activity in the area back in their day. The two sides are somewhat similar, but also different.

Whatcha' think ? Fossil or Indian item ? Someone also mentioned Lodestone, polished by Indians...?







Thanks.

[pickaway]

Could be,I've never seen anything like it.Looks thin also.Neat looking whats it.