Most often, when someone notices rings or water spots on their countertops, it is not a result of an improper sealing job. Sealing countertops is intended to protect the surface from absorbing liquids that might soak into them and cause permanent staining. A stain in your countertop will almost always appear darker than the surrounding areas. If you are noticing rings or water spots that appear lighter than the surrounding areas and disappear when the stone is wet, then you are actually seeing “etching.” This occurs when marble, or other calcite containing stone comes in contact with an outside element that is not pH neutral (most of the time, some type of acid). Unfortunately, every lot of marble reacts differently to acidity; so some countertops may etch very easily, while others may not. The only option for eliminating etching in marble is to protect it with a coating or film that will not allow acidic liquids or contaminants to come in contact with the stone itself.
