For anything else start with 600.
Wet sand marble countertop.
Wet the surface of the marble with a spray bottle.
Grinding unrepaired cracks will cause the edges to chip creating holes.
Spray a penetrating stone sealer on the marble countertops until the surface is wet.
Start with the coarsest grit sandpaper you have.
Allow the sealer to sit on the surface of the marble for up to five minutes.
Mix three tablespoons of soda with one quart of water and apply it on the surface then let air dry for several hours.
Saturate the surface of the marble countertop a second time and wait 30 minutes.
After washing it with warm water wipe crushed chalk on the countertop rinse again and dry with a chamois cloth.
Wet the surface of the sandpaper and marble.
Note use 220 when trying to smooth out irregularities.
In addition polishing grit or marble dust will fill.
If the cultured marble surface still isn t smooth and shiny try wet sanding with 1 000 grit wet dry sandpaper also available at auto supply stores followed by buffing with rubbing and polishing compounds to remove any scratches from the sandpaper.
For small blemishes uses 400 grit.
Another traditional method to restore the gleam of marble countertops is to polish them with baking soda.
Before you sand or grind a marble surface fill in any small cracks.