What i found at the beach?

Question

well when i was in like 4th grade i went to the beach....my parents told me not to go really far from them so they can keep an eye on me sooo i listen.....after a couple of hours of playing something caught my eye in the distance, it look cool so i ran for it and when i got to it it was a clam shell or something and when i flipped it over ......for some odd reason where were carvings of waves???? is this shell that i found man made or is it natural.... sorry i dont have a picture it broke to peices after i dropped it.

Answer 1

There are naturally occurring shells that have what look like waves 'carved' into them. But the waves are just growth spurts of the animal that made the shell.

Answer 2

sand