Marble Sealing
Some marbles stain more easily than others, and limestone is worse again. Red wine, olive oil and coffee all find their way in if the stone isn’t sealed. Sealing doesn’t change how it looks — it buys you time to wipe a spill up before it becomes a mark.
Acid is a different problem. Lemon and vinegar etch the surface rather than stain it, and no sealer stops that.