Help identify this artifact please
First time posting here.
Today whilst walking and looking for a good swimming spot , I found this artifact just up river from the Roman Bath house at Ribchester, Lancashire.
I found the usual collection of roof tiles and pottery shards, plus a fantastic hag stone and this lovely little thing.
They were all just laying in a rock pool that has been exposed in the middle of the river bed, you can walk across it in some areas because we've had a very dry summer.
I think it might be a portable whetstone but it is unfinished, the hole doesn't go all the way through.
The tool marks are clear to see , so definitely man made.
I have contacted my local "finds" team with the coordinates, pictures etc , but curiousity is getting the better of me.
Do any of you have any ideas?
It is illegal to dig or use metal detectors in this area , so I was very limited in what I could do.