Owners of stone counters may notice countertop discoloration over time; this can be caused by a number of factors. These blemishes can broadly be classified as either staining or etching, and each has its own preventive measures and repair methods. Therefore, it’s important to know what kind of discoloration you are dealing with, and which steps to take to both protect your stone countertops and fix any existing damage.
What is staining?
The porosity of natural stones varies greatly, and so does, of course, their absorbency. We seal our products during installation to help prevent staining; however, this process does not make the stone 100% impervious to liquid. Some stones may absorb liquids, and if such liquids are staining agents, a stain might occur. A stain is usually darker than the stained material, while the surface finish of the stone remains smooth.
What is etching?
Other “countertop discolorations” have nothing to do with the porosity of the stone, but rather are a result of damage to the stone surface. If the discoloration appears to be lighter in color (may look like “water spots” or “water rings”), it is probably an etch mark. An etch mark is a chemical burn that forms when acid, ammonia, or alcohol comes into contact with the calcium carbonate element that exists in certain natural stones. These marks look like the finish or the shine has been removed from the surface of the stone. The area that is etched can feel a little rough to the touch. Etching is most common on marble, some quartzites, travertine, onyx, and limestone surfaces.
Staining vs. Etching: A Video Demonstration
Additional Stone Countertop Resources:
How To Clean Stone Countertops – Learn our tips for cleaning natural stone countertops like granite, marble, and quartzite to avoid getting countertop discoloration from harsh chemicals and abrasive cleaners.
Sealing Stone Countertops – Read more about the misconceptions of sealing stone countertops and what we use to add an extra layer of protection to our stone.
Stone Countertop FAQs – Check out our answers to top questions we get from customers looking to buy stone countertops. Our countertop experts answer everything from picking out the perfect stone, to adding plumbing, and surface finishes.