Mineral deposits on stone countertops are common in hard water areas of the country, such as Hilton Head Island. Tap water is the root of this problem. The water piped into your home is loaded with minerals, and even with a purifier, water is only as good as the filter.
Water gets on your beautiful stone counter and as this water evaporates from the surface, the minerals in the solution are simply left behind. This is how mineral deposits can build up on your countertops and around your faucet. Deposits can appear as white or dull areas, but all is not lost. The granite underneath these areas can be restored to its original luster.
The methods for removal are simple. If there is a substantial build-up, it will appear white-ish and crusty. It is usually concentrated around the faucet, but can be in any areas where water has been left to sit and evaporate. A single-edge razor blade will not scratch granite and will remove most of the mineral crust. Use a fine gauge steel wool for the rest. Once you’ve removed all the build-up, the granite underneath should be good as new.
Keeping the area around the sink dry is a good preventative measure. Drying with a microfiber towel is a quick and easy way to keep your countertops free of dulling mineral deposits.