For anything else start with 600.
Wet sand marble countertop.
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.
Fill a clean spray bottle with plain water and spray a light coating of water over the marble.
Saturate the surface of the marble countertop a second time and wait 30 minutes.
Grinding unrepaired cracks will cause the edges to chip creating holes.
Before you sand or grind a marble surface fill in any small cracks.
Note use 220 when trying to smooth out irregularities.
Another traditional method to restore the gleam of marble countertops is to polish them with baking soda.
Start with the coarsest grit sandpaper you have.
Wet the surface of the marble with a spray bottle.
Wet the surface of the sandpaper and marble.
After washing it with warm water wipe crushed chalk on the countertop rinse again and dry with a chamois cloth.
Spray a penetrating stone sealer on the marble countertops until the surface is wet.
For small blemishes uses 400 grit.
Wrap it around a block of wood or sanding sponge.
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.