What type of mop should I use on my marble tile floor? Sponge or string mop?

A string mop is preferable to a sponge mop. A sponge mop has a very small surface area, and can easily pick up sand and debris which will scratch the floor. It has been shown that after several swipes with a sponge mop, you are only spreading the dirt around the floor. Most janitorial supply houses sell good-quality string mops. I recommend a cotton-blend mop with sewn ends. The sewn ends allow the mop to be machine-washed. Be sure to use this mop only on your stone floor.

TIP If you machine wash you mop head do not dry it in a drier. Allow the mop head to dry by hanging it over a clothes line.