Most people would consider marble the most beautiful stone you can add to any room in a home or office. However, many people see marble as difficult to clean and manage. This is an unfortunate consequence of marble being very susceptible to etching caused by acids in marble cleaners.

Marble is made up of calcium carbonate (CaCO3), which is highly reactive to even mild acids. When marble encounters an acidic agent, the acid dissolves parts of the marble surface exposing marble that was once below the surface. This newly exposed marble is unpolished unlike its surroundings. Consequently, these etch marks show up as dull whitish marks compared to its nice polished surroundings.

One of the most common causes of etching occurs from inexperienced marble owners trying to clean their marble. Many household cleaners contain acids as active ingredients, and once they are added to the marble surface, small light marks begin to show up on the surface.  Therefore, it is very important to be aware of marble’s one big vulnerability and, thus, choose a safe marble cleaner.

What makes a safe marble cleaner?

A safe marble cleaner must not be even the slightest bit acidic. A strong acid will almost immediately create etch marks on marble, but a mild acid can get you in even more trouble because they are deceptive. You will not initially notice the damage, so you will continue to use the mildly acidic cleaner, and, before you know it, you have dulled the entire surface. To insure your cleaner is safe, the pH level of the cleaner must be above seven. Ideally, the pH level will be slightly higher than seven, so the cleaner will have some cleaning power.

For some reference, pure water has a pH level of seven, so to increase the cleaning power of the cleaner, the manufacturers of safe marble cleaners typically increase the pH to somewhere between seven and 10. Since a mildly basic solution is safe, these cleaners have the right balance of pH to be safe but effective. For more information, see this article on the role of pH in cleaning.

How to choose a safe marble cleaner

Due to the sensitivity of marble to acids, it is best to use cleaners that are specifically designed for marble. Therefore, safe cleaners will say “marble cleaner,” “safe for use on marble,” or maybe “pH balanced.” These cleaners are designed for marble and should be safe for use. To be extra careful, read the backside of the cleaner and see if it offers the pH level of the cleaner. Look for a range of seven to 10, maybe a pH of 11 for specific-purpose cleaners like soap scum removers. For more information, see this article on selecting marble cleaners.


Owen Franklin is the creator of TheMarbleCleaner.com, a site filled with completely free resource that is a one-stop-shop for everything you need to know to maintain and care for marble. TheMarbleCleaner strives to give actionable, easy-to-use, marble care and maintenance tips.