Raw marble, whether in slab or block form, is marble that has not yet reached its full potential. Until it is polished, marble is dull and cloudy. Once the marble has been polished to a high shine, you can see all of the color variation and movement that makes the stone so valuable. Whether you are planning to install marble on your counters, use it as a base for a table or create a piece of art, the marble needs to be polished to bring out its luster and shine.
Wipe the outside surface of the stone with a damp rag. Brush away any debris and sand that might scratch the marble’s surface during polishing.
Put on goggles and attach a coarse grit sanding pad to your hand-held grinder. Wet the surface of the marble with clean water. Turn on the grinder and lower it to the marble. Move the grinder back and forth and up and down to begin polishing. Sand the entire piece.
Change the sanding pad to a finer grit pad. Pour water over the surface and sand the marble again.
Repeat this process, changing to finer sanding pads each time you sand, until you get an appropriate amount of shine. Polishing marble is slightly subjective. You should polish until you like how it looks.
Place a buffing cloth on the grinder. Dip your finger into marble and granite polish and rub it over the buffing cloth. Buff the marble to a soft shine.
Pour a small amount of impregnating sealer onto a soft t-shirt or rag. Rub the sealer into the marble.