What’s the Dark Ring Around my Granite/Quartzite Sink

By Frederick M. Hueston

You’ve probably heard of ring around the collar, and in the stone business, we sometimes refer to it as “ring around the sink” or “ring around the profile.” Recently, I have been inundated with inquiries on the reason why particular granites and quartzites begin to form a dark ring around the perimeter of the sink and sometimes around the top edge of the profile. This darkening can occasionally appear shortly after the installation, while other times it can take several months before it becomes noticeable. What factors have contributed to this darkening, and more importantly, how can it be remedied?

 The formation of a dark ring around the sink or profile of granite and quartzite is a common occurrence, and several factors can contribute to its development. One primary factor is the accumulation of soap residue, body oils, and other substances that are not entirely removed during regular cleaning. Over time, these substances can create a dark and unsightly ring that can be difficult to remove.

Another factor is the porosity of the stone. Certain granites and quartzites are more porous than others, which makes them more susceptible to staining and discoloration. Additionally, the type of sealer used during installation can play a role in the formation of a dark ring. If a low-quality sealer is used, it may not provide adequate protection against staining and discoloration.

Not sealing the underside or sides of the stone can also cause moisture to soak in causing these rings.

Also, the use of certain caulking types such as silicone and acrylics that are used to seal the sink to the stone can bleed into the stone causing it to darken.

Fortunately, there are several remedies for these issues. The first step is to thoroughly clean the affected area using a mild soap and warm water. For stubborn stains, a poultice can be used to pull the stain out.

To check for moisture use a moisture meter to see if the darkening is moisture. If it is moisture, it can sometime be dried out by carefully using a hair dryer or heat gun.

If the staining is caused by the caulking used than the sink may have to be removed, the caulking scraped away, a poultice applied and then reinstalled with a non-staining caulk.

 Once the darkening has been removed, it is crucial to apply a high-quality sealer to protect the stone from further staining and discoloration. The seal should be applied to the sides as well as the overhang on the sink.

While ring around the sink may be an unsightly and frustrating issue, it is a common one that can be remedied with proper cleaning and the application of a high-quality sealer.