Best you see it in the dark

[grassfarmer]

I got those too, i call them wild potatoes.

Had a beginner farmer as a neighbour in Scotland - he came from Glasgow and was a real city fellow. He classified stones into 2 types - the bigger ones were "bricks" and the smaller ones "chuckies" (derived from chuck i.e to throw in Scottish slang - apparently in Glasgow you routinely throw small stones at the other city dwellers) Took a bit of figuring out initially LOL.