To cut a marble countertop:
Wide tape, a circular saw with a diamond blade, safety goggles, a 2-inch foam slab and a water hose are needed to complete the project.
Cut on the foam slab to protect the work surface and marble. Measure and mark your cuts and tape off the cut line with the wide masking tape. Trickle water in front of the blade to cool it, wear protective goggles and cut the marble.
If needed, use a orbital sander to smooth the cut edges of the marble.