We seal your counter tops with two coats of a commercial grade sealer at the end of the installation.
Sealer should actually be referred to as retarder because it retards the absorption time of various liquids and does not form an impenetrable barrier. Because different solutions pass through the sealer at different rates combined with the fact that stones have varying compositions and densities there is no easy answer as to how long a liquid can sit on the surface until it will produce a stain. The best rule of thumb is to wipe it up as soon as conveniently possible.
How often should I reseal my counter tops is the most widely asked question, and again there is no universal answer. The rule of thumb is approximately 1-year.
The sealer can last up to three years depending on which sealer you start with and what you clean the stone with. Your first choice should be a cleaner specially formulated for stone such as Revitilizer by StoneTech which are available at our showroom as well as many other stone care products. This product has a neutral PH which will not degrade the sealer which was applied at the installation and actually contains a small amount of sealer to replenish the existing sealer. It also contains an antimicrobial agent to disinfect as it cleans.
This is the preferred cleaner, but you can always use a mild dish washing detergent and water. Please do not use Windex, Fantastic, Mr. Clean, etc, etc. While they will clean the stone they also degrade the sealer.