Will cause When an acidic solution comes in contact with the stone, a dull spot is the result. The acid “eats” the stone leaving dullness, or etching behind. Penetrating sealers help to reduce severity of etches, but cannot eliminate them. Depending on acidity, some liquids can etch immediately, such as wine, where milder acidic solutions may not etch with proper penetrating sealing. More on the stone surface resulting in a dull spot. Acids dissolve tiny particles of stone.