How to restore dull areas on bathroom quartz countertop?

Try car wax

https://www.youtube.com/watch?v=DlFMWao8WAo

https://www.google.com/search?q=dull+areas+quartz+countertops&source=univ&tbm=shop&tbo=u&sa=X&ved=0ahUKEwjY2ZnX2p3gAhUPXKwKHZeYDu8QsxgImwI&biw=1525&bih=722

https://www.youtube.com/watch?v=RlfT0HTYOTs

Try a product from the floor wax section of your grocery , one that says you can use on counter tops or quartz. I have seen this in the grocery section of Walmart.

Hello Virginia, hope this helps you out,

Materials Required

• Warm, Soapy Water, Sponge & Vinegar
• Two Soft Towels, Spray Bottle Filled With Distilled Water
• Window Cleaner And Paper Towels

Procedure

• Cleaning The Countertop: Start by using the soapy water and then scrub down the surface of the countertop. The users don't have to keep worrying regarding the scratching as the quartz countertops are not the delicate material at all but still the users are advised not to use the abrasive pads. Although the abrasive pads won't damage the quartz countertop surface it can leave residue behind and may dull the countertop polish as well. In order to get rid of specific hard stains, the users are advised to apply the few vinegar drops to the spot and then cover up the spot with the damp rag for almost a few minutes so that the junk gets to loosen up. The users are advised not to use the oil made soaps as they can leave their residue behind.
• Thoroughly Rinse: The users then need to use the spray bottle so as to soak up the entire surface of the countertops. Most of the streaking usually comes within the food or the soap residue but these kinds of countertops are having the nonporous surface and the liquid won't get absorbed into its surface and that can leave the film over the countertop surface. The users need to use the sponge so as to scrub down the quartz countertop and then clean off the excess water by using the dry cloth. The users need to be assured that there is no streaks leftover the countertop surface when it is dried thoroughly.
• Spray Window Cleaner: The window cleaner is having the great feature that they are having the powers to cut the grease. Mainly in the kitchen area the grease often gets dispersed within the air when the users are cooking and that can then settle over the countertop surface and will create the gunky film. In order to get rid of the cooking film the users can spray the window cleaner over the entire surface of the countertop. The users are advised not to overspray the window cleaner. Then they need to wipe down the cleaner by using the soft cloth or the users can use the lint-free cloth for the cleaning process. The users can easily purchase any organic and natural window cleaners at their nearby home improvement stores.
• Don Not Use More Polish: The quartz countertops are already having the sealed surface and that is why by adding the more polish can only create the unneeded buildup that can further dull the countertop look.