Hello everyone, concave stone here.

[Olivinetoothedcreeper]

I bought a metal detector and ended up collecting rocks... But Sorry for the quality, my phone is ancient. I was wondering if this is an old chipped Fire starter or an oddity of nature? The area was home to Erie then Iroquois originally, I didn't read about them until after but this looked special when I first saw it. It feels like it was held in the hands a bit by the polish. Thanks and hello.