Help identifying what I've found

[Farm]

Hello,
stumbled across this forum while trying to find some information on geology, I'm after some advice on two finds I have. The first one was found in a small stream and the other in a cultivated field not far from where I live. Any advice would be great, they might be very common but I thought they where both usual and would like some info on them if possible.

 

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[ToddsPoint]

Last one is a concretion of some sort. Gary

 

[RustyGold]

Welcome to TreasureNet. Good luck with the ID!