A recently laid marble floor will have a glossy, reflecting sheen that will change appearance depending on the lighting in the room. This will give the space an air of sophistication. On the other hand, this finish has a propensity to become less shiny with time, losing its shine as the tiles become scuffed and damaged. This may provide a challenge to have restoration, particularly if you are getting the house ready to be put on the market. Cleaning your marble floor at this point won't make much of a difference; cracked or scratched tiles will always seem dirty to some extent. However, there is still hope for a marble floor that has been damaged. You are able to return the floor to the splendor it had when it was first installed. 
It is possible to restore the finish of your floor by performing some hand effort. This involves restoring the surface and polishing it to a shine, which makes the marble appear as beautiful as it did on the first day it was placed.
- Search the surface of the floor for any tiles that are cracked or loose, and then remove those tiles to be replaced. Use a utility knife to cut the grout out of the joints surrounding the tiles that you are removing. This will allow you to remove the grout that was surrounding the tiles. To remove damaged or loose tiles from the floor, position the pointed end of a prybar under the tile, and then apply force to the bar to pry the tile up and away from the floor. Put the tiles in a separate pile.
- Remove the mortar from the subfloor that was underneath the tiles that were removed. The mortar was what held the tiles in place. Remove the mortar by using a rotary tool equipped with a carbide blade and scraping it away. Please turn on the blade while holding the instrument so that it is perpendicular to the mortar at a 45-degree angle. After cutting through the mortar to reach the flooring below, move the blade against the subfloor to remove the mortar, and then continue moving the blade along the subfloor to finish. Put the tool away and use a broom to remove the mortar from the subfloor's surface.
- Using thinset mortar, reattach the tiles to the floor in the same position they were in before they became loose. Using a steel trowel with notches in it, you should first spread the mortar over the back of the tiles. Next, you should use the notches in the trowel to raise the mortar into a series of ridges that will provide greater holding. Applying pressure to the tile will ensure that it is adhered to the floor in the correct alignment with the other tiles and with the same amount of space between them. Using a carpenter's level, check to see if the tile in question is flush with the tiles around it. Make any tile modifications that may be required. Replace the tiles that are broken with the entire tiles that have been purchased to match the tiles that are already in the room. Remove any extra mortar from the tile's surface as soon as possible, and then wait two hours before cleaning the mortar off the tile.
- Re-grout the joints that are adjacent to the tiles by spreading the grout across the tile surface using a grouting float in order to fill the joints completely. Use a wet sponge to wipe away any extra grout from the tile's surface within 15 minutes of applying the grout to the tiles. After waiting two hours, clean the surface of the tiles with a cloth that does not contain lint in order to remove any grout residue before it sets into place and becomes permanent. Wait twenty-four hours to give the mortar and grout enough time to begin setting before proceeding with the floor restoration.
- By honing the surface of the marble floor tiles, you may remove any scratches that may be present. The scratches can be removed by using an orbital sander with sandpaper that has a grain of 100 and running it over them in small circles to grind the edges of the scratches down to the tile's surface. This will result in the appearance of light lines on the tile. Alter the grit of the sandpaper to 150, and then use the sander to grind away at the marble in the areas where there are light lines. Continue this process until the lines are no longer visible. Sand the surface of the tiles one more time, this time using sandpaper with a grit of 220, and this should leave the tiles feeling smooth to the touch.
- To polish the floor tiles, use an angle grinder with a polishing pad that is 4 inches in diameter. After that, set the pad onto the tile and then pour a circle of polish onto the pad about the size of a quarter. To polish the tile's surface, turn on the grinder and use the pad to polish the tile's surface while spreading the polish across the tile. Allow the nail polish to dry completely until it becomes a gray color.
- Reposition the pad so that it is resting on the tile, then turn the device back on. Repeat the process of buffing the grey polish until it reaches a glossy finish. There may be a need for more than one treatment in order to polish the tile to the desired degree.
- To keep the marble from becoming stained, apply a thin layer of stone sealer to the surface using a paintbrush. Before walking on the marble floor again, you should give the sealer at least 48 hours to dry.