Granite stone is the most popular stone used in countertops. It comes in a wide variety of colors, and may be installed using large, thick stone pieces cut and polished by a professional stone company or it may be installed by a homeowner using either precut tops or tiles. In general, granite is a durable stone with few problems, if installed and maintained properly. However, due to differences in granite composition, the maintenance of this countertop varies based on how porous it is. The granite experts at keidel.com note that if your countertops are dark black or green, the stone may be so dense that the countertop doesn't require a sealer. In this case, an applied sealer may not penetrate the surface of the granite and the sealer itself may cause a dulling to the granite's appearance. In addition, because of the popularity of black countertops, some companies have applied color enhancers to less-dense, dark gray granite to mimic the appearance of a true black. It is important to determine what you have before you start. It is also important to determine if your granite has a honed (intentionally dull) surface.
Clean your countertop thoroughly with a mild detergent or pH-balanced neutral stone cleaner. Remove all stains and grit or they will be sealed into the granite. It is better to use a pH-balanced neutral cleaner or a cleansing product specifically designed for stone countertops. This will eliminate soap residues, which are a common source of dulling. Specialty pH-balanced cleaners prevent acid etching, which damages granite surfaces. Simple Green and Brightstone offer stone cleaning products.
Remove any existing wax with #0000 grade steel wool or a stone wax removal product. Wipe with water and dry with a soft cloth.
Let the countertop dry out for two to four hours hours, depending on how porous your granite is. The counter needs to be completely dry before applying sealer.
Apply the sealer according to the manufacturer's instructions. Use a spray bottle to help apply the sealer evenly. Wipe off any residue and let your countertop dry thoroughly. See Resources for links to sealers.
Apply an automotive rubbing compound, such as Flitz to dull areas, then apply a Carnauba-based wax, such as Flitz, and buff using a standard car buffer until the shine returns. Alternatively, use a silicone-based stone polish product, such as Italian Craftsman. Silicone-based products produce a higher shine, but may also leave a greasy or slimy appearance. Or, use a non-silicone based polish like Lithofin's Stone Conditioner & Polish. This product has a reputation for producing a nice finish when it is buffed out. A good wax shine is produced by products such as Pamir, a thick paste wax. This type of wax can produce good results along edges as well, but it is more labor-intensive than thinner wax applications.