I would appreciate input on a problem. I need to remove a wine etch marble on a marble floor. Simple enough, but this floor has a coating.  I may be wrong, but it appears that it is crystallized.  I have no experience working with crystallized floor. Perhaps the etch mark will come out with 5X. If not, I assume the steps would to hone the area say up to 220 to 1800, and then crystallize the area. Would that be the correct procedure? Also does anyone know the shelf life of crystallizer? I have spray bottle of the stuff I about 5 years ago. Would that stuff still be viable? I will 1st test this in a hidden area.

See attached picture!