NCF Stone is designed to be used specifically with natural stone such as granite and marble, especially light-colored varieties of granite which are prone to discoloration when too much of our NCF Quick is used. We have tested this product on a variety of these sensitive granite types, and they did not discolor even when completely soaked with NCF Stone. However, NCF Stone should still be applied as a light mist- if the parts are becoming visibly wet, you are applying too much.