I recently got some contractors over to repair a section of my house and they unknowingly spilt a small amount of acid on my marble floor.
They did not attend to it immediately and the acid corroded the surface of the marble floor.
How do I repair it?
You would normally clean marble with etch spots with hydrogen peroxide or bleach and then repolish. From the sound of it yours may be more severely damaged. I would try both on a small spot and see how it goes.
If your marble is actually corroded then you will have to polish until you hit uncorroded marble.
Corrosion of marble (a form of metamorphic limestone) is not a stain, but rather a dissolving of the base rock.
The solution (if not too deep) might involve surface grinding, honing and polishing in place, but is not a DIY project. Discuss with a marble installer/fabricator.
Another solution (if the marble tile is available) is to replace the one tile.
