Granites and Marbles should be periodically re-sealed with a high quality stone sealer to maintain their resistance to staining. Counters should be de-greased with a mild dish soap and left to dry 24 hours before re-sealed. Deeper stains may require expert assistance to remove stains. Re-sealing should be done every 6 months for lighter colour stones and once a year for darker stones. For everyday cleaning avoid harsh chemicals,such as bleach or bleach based cleaners, ammonia (i.e. Windex), vinegar, or CLR. Use mild soap solutions. Quartz based products advertise that they do not need sealing.