Marble is an incredible natural material to use for flooring... and the best part is that polishing it requires no harmful chemicals. You can get LEED credits for using it, and it looks gorgeous in homes and businesses alike. I've found a lot of great information about polishing marble floors at http://www.marblefloorpolishing.com . If you're thinking about installing marble in your house, or you want to refinish it, it's a great place to go. They have a pretty extensive directory of contractors by area, as well. I would highly suggest checking it out