This is an example of a neolithic carved ball, which I came across whilst visiting the Isle of Lewis in 2006.
I've found a number of these on my travels around the British Isles. Kilmartin Glen in Scotland has a lovely museum, and has a number of examples of them. Some are exquisitely carved, and have lots of geometric surfaces on them; others are very crude, and hardly marked at all.
In my painting 'Moontree', I used these different shapes as part of the design. Some are depicted as 'carved', and marked. Others in my painting were simply coarse 'blobs'.