General daily cleaning with hot water and a cloth or sponge; or, you could use either soapy (mild detergent) water or an ammonia based cleaner: rinse and towel dry afterwards to avoid watermarks.
For infrequent disinfecting, use a mixture of equal parts of bleach and water and simply wipe down with water afterwards.
These surfaces scratch quite easily, so use a chopping board when preparing food and never chop directly on the surfaces. However, if scratches or discolouration occur, remove by a light sanding with the correct grade of sandpaper.
For ongoing maintenance on matte or satin finishes, a light rubbing of the surfaces with a scotchbrite pad will restore them from their daily wear and tear.
Daily cleaning should be with warm water and a mild detergent, then rinse and dry the surface.
Occasionally use a scotchbrite or other delicate scrub pad, rinse with clean water and dry: this will keep the surface good as new.
To remove stubborn or stuck on stains and spills, use either a non abrasive household cleaner maybe together with a no scratch scotchbrite pad; again rinse properly with clean cool water and dry.
Ideally it should be cleaned each time you use it as it is really porous and thus most likely to stain.
Use only warm water and a limited amount of mild soap applied with a soft cloth or wet sponge. The mild soap should be a non invasive detergent. Rinse with clean water and dry. Even after sealer has been applied granite can be porous.
Do not use anything acidic, say, vinegar or ammonia as these will do harm to your surface. Look for the special cleaning kits for granite on the market.
Not really affected by heat, marble countertops can stain easily because they are porous. Clean whenever used to prevent staining and discolouration. Avoid use harsh cleaners, detergents or other regular cleansers – not even vinegar and water - as these can damage the surface. Rather use borax powder – which is readily available and inexpensive. Rub it onto the surface with a damp or wet cloth. After removal of the stain or dirt, rinse with clean warm water and dry the surface with a soft cloth.
For frequent maintenance, the countertops should be regularly sealed and resealed when water starts to absorb into the surface and doesn't remain on the top. This sealing will also reduce the risk of stains and keep the surface looking at its best.