Why marble etches

Marble is limestone that has been recrystallized by heat and pressure. Its main mineral is calcite, which is calcium carbonate, and calcium carbonate reacts with acids. Lemon juice, vinegar, wine and many cleaners will dissolve a microscopic layer of a polished surface and leave a dull spot where the shine used to be.

That dull spot is an etch, and it is different from a stain. A stain is a liquid that has soaked into the stone; an etch is a chemical change to the surface. Sealing slows staining but does not stop etching, because the acid attacks the stone itself.

Etches show most on dark, polished marble and least on pale, honed marble, where the finish never had a mirror to lose. Many owners choose marble precisely because the surface ages and gathers character, and a fresh etch can often be re-polished.

If you cook hard and want zero change, a quartzite, quartz or porcelain surface is the better fit. For a bath, a vanity or a feature wall, where nothing acidic lands on it daily, marble is hard to beat. That is why we recommend by room and by use, not by trend.