Granite countertops are extremely durable, but just like anything else, they have an Achilles heel. Oven cleaner can permanently damage their color. This applies to all types of granite countertops, including polished surfaces. In addition, avoid using bleach, ammonia, scouring pads, or other abrasive cleaners.
With quartz countertops, oven cleaner will also cause permanent damage. Over 90 percent of quartz contains polymers and pigment. The polymers in the resin are lighter than the quartz and can cause surface damage and discoloration.