For anything else start with 600.
Wet sand marble countertop.
Saturate the surface of the marble countertop a second time and wait 30 minutes.
Wrap it around a block of wood or sanding sponge.
Note use 220 when trying to smooth out irregularities.
Allow the sealer to sit on the surface of the marble for up to five minutes.
Another traditional method to restore the gleam of marble countertops is to polish them with baking soda.
Fill a clean spray bottle with plain water and spray a light coating of water over the marble.
For small blemishes uses 400 grit.
Mix three tablespoons of soda with one quart of water and apply it on the surface then let air dry for several hours.
By wetting the marble before you sand you ll give the dust something to stick to so it will form a paste rather than flying into the air where you could inhale it.
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.
After washing it with warm water wipe crushed chalk on the countertop rinse again and dry with a chamois cloth.
Grinding unrepaired cracks will cause the edges to chip creating holes.
Start with the coarsest grit sandpaper you have.
Before you sand or grind a marble surface fill in any small cracks.
Wet the surface of the marble with a spray bottle.