Marble etching,
and how to stop it.

Marble, limestone and travertine are made mostly of calcium carbonate. When an acid touches them, it reacts with that calcium carbonate and dissolves a microscopically thin layer of the surface. What is left is rougher than the stone around it, so it scatters light differently. On polished marble that shows as a dull, cloudy patch. On honed marble it can look like a lighter or slightly rough spot.

It happens fast. A few minutes of lemon juice is often enough.

Common causes in a Sydney kitchen

• Lemon, lime and other citrus
• Vinegar, salad dressings and tomato-based sauces
• Wine, soft drinks and fruit juice
• Many bathroom and kitchen cleaning sprays
• Some cosmetics, perfumes and toothpaste on vanities

Most marble is sealed when it is installed, and many owners are surprised when it still etches. That is because a penetrating sealer works inside the stone, filling pores to slow absorption. The surface is still calcium carbonate, and acid still reacts with it.

To stop etching, the acid has to be kept off the stone altogether. There are only two ways to do that: wipe every spill immediately, every time, or put a physical layer on top of the marble. That is what an anti-etch protection film is.

We compare the two approaches side by side in sealer vs protection film.