What brand of neutral pH soap is safe for polished marble flooring?

There are several stone soaps available from Stone Tech (available at Lowe's as DuPont), Aqua Mix, Miracle Sealants (available at Home Depot). Before mopping on natural stone, please make sure that you vacuum well so there is nothing left to scratch the surface of the stone, especially polished stone. The easiest way to clean the floor is to spray the floor with stone soap and than use a steam cleaner. You use much less water and the steam evaporates and the floor dries in minutes. I've never liked the results of a string mop, personally I thing a sponge is better. I recommend steam cleaners on all types of stone. If you have any more questions about stone, please visit my blog and ask them. http://artearthstonetiles.blogspot.com/