This is an automated archive.

The original was posted on /r/whatisthisthing by /u/_bootleg on 2023-09-04 17:00:52+00:00.

Original Title: Weird round stone thing found on Brighton beach, UK. It has a raised bump in the centre with evenly spaced grooves around it. Exactly 3x3cm. It’s not ceramic – we thought it was a pebble til we turned it over.