Neolithic polishing stone found in Dorset

[Duncan Head]

https://www.theguardian.com/science/2023/jul/14/hugely-exciting-and-rare-neolithic-polishing-stone-found-in-dorset

OK it's prehistory, but interesting.

[Imperial Dave]

Still interesting absolutely

[Jim Webster]

I've seen them by church doorways where people apparently polished arrow heads, and I know a farm where a sandstone windowsill was polished by men sharpening pocket knives.
Indeed I remember seeing one sandstone kitchen sink which could only hold half the water it should have done because over the years too many kitchen knives and others had been sharpened on it 

It's old technology but it's not obsolete technology