Stone the crows?

The MonoMonday challenge theme from JacZero is stone, and it prompted me to top up this birdbath, which is actually a small, solid granite replica of my christening font. It’s a present given to me by a long departed grandparent., has my birthdate and initials inscribed and has moved with me to the eleven different homes I’ve lived in,  I don’t know whether to try and clean it sometime, or let its weatherbeaten facade continue to match my own!