Limestone does not rust, but the metal fixtures attached to limestone do rust and in our case - this is what happened. NOw the limestone is stained. This is a valid question. Our home is over 100 years old, so I am interested in learning about a process that will remove the run without damaging the stone. Any one? Thank you.
Poultice with Oxalic acid + powder + water. This poultice will etch polished marble, limestone and travertine and repolishing will be necessary.
I'd try vinegar first...a light acid...if that doesn't work use a rust remover for laundry and scrub brush...if you're not too worried about the stone, then just go get some muriatic acid, masonry section of hardware store
Limestone dosen't RUST! SO WHY DO YOU want to NO HOW TO CLEAN IT!1