I have a marble top in the bathroom with a circular white stain that is raised and dull against the shiny finish of the marble. I believe it is limescale or perhaps the result of Viakal cleaner.

I have tried gentle and not so gentle cleaners without luck.

Is there a way to restore this area to its original uniform and shiny look?

Is there a way to do a mechanical "spot" polish?

Are the marble polish cleaners any good?

Thanks.