Marble, granite and other natural stones are porous and therefore can be susceptible to staining. Delicate colours may alter or fade when cleaned with unsuitable products or exposed to sunlight. Caring for your stone surfaces correctly will ensure their continued aesthetic beauty. Marble, granite and other natural stones are porous and therefore can be susceptible to staining. Delicate colours may alter or fade when cleaned with unsuitable products or exposed to sunlight. Caring for your stone surfaces correctly will ensure their continued aesthetic beauty.