pyrite acorn?

[rockhoundrich]

Found this at a yard sale persons grandfather was a rockhound i got some other nice sp

 

[mamabear]

I have found pyrite that grows in a circular pattern, or described as radiating. None I have found look quite like yours, though it could possibly be the growth pattern. I would not discount fossil. Wait for our more knowledgeable members put their 2 cents in

 

[rockhoundrich]

Thanks MB ive never seen anything like it either although i know its possiable