From what I can see, these are broken marble. Not the most expensive type but it is nice. Personally, I think you will be OK to do the grinding and polishing and it will be quite new. Of course, deep stains and cuts or scratch still can't be fixed. You really need to show a real picture to be able to comment accurately. If it is just lacklustre, you can make it shinny again.

I kept my marble floor when I am doing my renovation. You could save the money and spend it elsewhere. Like I said, unless your marble floor is in really bad shape, no point changing to others. Well, except you decided to change it to compressed marble or compressed quartz which are tougher and yet has the natural stone look

This post has been edited by bhtan: Jul 18 2011, 03:49 PM

But marble is quite porous. All the polishing and grinding will not help if there are deep stain or scratches.