The acid in the lemon has etched the surface of the marble. The only option is to re-polish or hone the marble. Polish the etched area using a powder polishing compound. Work the powder into a slurry using a white pad and a slow rpm hand buffer. If the etch is light, you may be able to remove the etch by hand. In this case rub the powder into a slurry with a white pad and work in a circular pattern. Once the etch is removed apply a good quality marble paste wax to help prevent etching.
Article ID: 609
Created: January 21, 2022
Last Updated: January 21, 2022
Author: Pam Freitag
Online URL: https://sr-manual.com/kb/article/a-lemon-slice-sat-on-our-marble-bar-top-overnight-and-left-a-white-mark-how-can-we-remove-this-mark-609.html