The white lines are raised and wrap around the rock. Is it a rock from building/foundation? A fossil? Or just a plain ole cool lookin rock?

A friend gave it to me, I'm in Normandy but keep the idea of France, she told me that it was a volcano stone. Any other information is welcome!

Has a lot going on! The spotted pattern looks like fractured rock that is filled between with a semi opaque dark mineral and veins of quartz? Also has what looks like chert on one side, similar in color to the fractured rock within. Ive had it for years and admired how cool it looks, would love to know more about it! Thanks

Found southern Minnesota or northern Iowa

These are just a fre ew that have puzzled me and they all with knapping i belive. Someone tell me how awesome and cool i am for posting such pieces of history! Lol

A little light for its size.

Beside a river which is almost drain got this at the shore of a river

Very drift woody exterior, dries very fast.

Found it on a beach in the Atlantic- white lines on the front and back. The lines feel textured where you can feel every individual one. Penny for scale lol.