Moisten a dishcloth with warm water. Wipe loose dirt and fresh spills off the quartz countertop.
Pour 2 oz. of neutral pH household detergent into a container. Add 1 qt. of hot water, stirring it into the detergent with a spoon.
Dampen another dishcloth in the solution. Wipe any remaining dirt, grease or stubborn oil-based stains off the quartz countertop.
Saturate a fresh dishcloth with water. Wipe the detergent solution and loose residue with it, and then thoroughly rinse the countertop.
Absorb the water from the quartz with a dishtowel. Dry the countertop thoroughly.
Moisten a dishcloth with warm water. Wipe loose food crumbs and beverage spills off the quartz countertop.
Mix 4 oz. of 12-percent hydrogen peroxide and 1 tsp. of household ammonia into a spray bottle. Douse the remaining food and beverage stains with the solution.
Dampen another dishcloth with water. Wipe the food or beverage stain and the hydrogen peroxide solution off the quartz countertop.
Wipe the water off the countertop using a dishtowel. Then, thoroughly dry the countertop.