Managed to scratch the crystal of my U1 yesterday -
A pretty unremarkable happenstance, except it's not the AR that's scratched - I removed it yonks ago as its previous owner had already damaged it - no, it's the ruddy sapphire itself!
Something in our so-called 'granite' (actually a dolerite of some sort) worktops was hard enough to abrade it. It's not
impossible that there's some corundum in the stone I guess.
Faintly irked TBH, as I'd not expect it to get scratched, but it's a tool watch and already has some very light marks in the metalwork, so I can live with it.