Dull marble. The polish is worn, not dirty.

What it is.

When a marble floor or benchtop goes dull across the whole surface, it is not dirty. The mirror finish on polished stone is mechanical, produced by fine abrasives, and it wears away under feet, pots and cleaning. Once it is gone the stone scatters light instead of reflecting it, and no cleaner will bring it back. Polishing does: the surface is worked back through a sequence of finer and finer diamond grits until it reflects again. This is the most common job we do and the most satisfying, because the change is total and the stone underneath is nearly always sound.