Before we get into the polishing, and restoration process, let's discus why your stone gets damaged in the first place.
There are 3 main types of damage to stone: scratching, moisture absorption (including staining) and etching.
All natural stone is susceptible to scratching. Some stone are easier to scratch than others but if you try hard enough they all get there eventually.
All natural stone is susceptible to moisture absorption. Though, again, some stone absorb moisture more readily than others. Moisture absorption can lead to all sorts of problems; erosion, flaking, peeling, efflorescence, detachment, freeze-thaw cracking, staining, etc. Once these start it can be difficult to stop them and often leads to the need to replace the stone.
Marble, along with other calcium carbonate based natural stone, (limestone, travertine, onyx, etc.) are prone to damage from acids. These acids, be they cleaning agents, food, cosmetics, etc., when they come into contact with the stone they begin to dissolve your stone, and negatively impact the stone surface. These acids corrode the stones surface, leaving a dull etch mark. The longer these acids are in contact with the stone the more severe the damage. Etch marks have a lightening or bleaching effect on the stone and cannot be cleaned off. Etch marks are sometimes confused with staining though they are not the same thing. A quick way to tell the difference is that etch marks lighten and stains darken your stone. Just as a quick side note, a true granite won't etch, which is why when you spill lemon juice on your granite counter tops and it drips onto your marble floor, the floor gets etched and your counter top stays looking good. (and now has a nice lemon fresh sent to them)
So how do you prevent these damaging from happening in the first place?
Scratches are caused by something abrading the surface of the stone. Dragging your refrigerator across the floor, or just simply walking across it, both activities will scratch your floor. The scratches from the fridge you will see right away, the scratches from walking across your floor will take longer to see, (unless you have a nail or rock stuck under your shoe) There is microscopic dust on your floor and when it's tracked underfoot it will causes microscopic abrasions that, over time, lead to a dulling effect on the stone. A daily removal of the microscopic dust particles on your stone can help preserve the stones finish. A dry micro-fiber cloth or a vacuum with a soft bristle brush should do the trick. (as for the fridge, we recommend using a dolly) When a wet cleaning is required, perhaps once or twice a month, be sure to use a pH neutral cleaner diluted in water. (follow the manufacturers guidelines) You can buff the stone dry with a soft cloth to avoid "mop streaks"
Moisture absorption, and its damaging effects, can be avoided or diminished by having your stone sealed from day one with a penetrating sealer, (Do not use a topical coating on your natural stone) and then having it re-sealed over time as needed. This need will very depending on the location of your stone, the type of stone, and the type of penetrating sealer used. Again, do not use a topical coating on your stone as they can contribute to some of the above-mentioned problems. A penetrating sealer will not change the look of your stone, and it will not protect against etching or scratching. A penetrating sealer is meant to do one thing, protect against moisture absorption. By preventing moisture absorption, you help protect your investment in your stone for the long term.
Etch marks are easy to prevent, just keep everything acidic away from your acid sensitive stone (marble, limestone, travertine, onyx, etc.). It's harder said than done but cutting boards, coasters and placemats can help. If you do spill something on your stone, wipe it up right away, as the longer it sits on your stone the more damage it will cause. Oh, and never clean your stone with vinegar, it's an acid and will damage your stone.
Dry sweep or vacuum your stone regularly to remove dust and debris.
Wet clean your stone, use a pH neutral cleaner.
Use a dedicated microfiber or a soft cotton cloth when cleaning your stone.
Use coasters, placemats, cutting boards and trivets.
Clean up spills right away.
Use a squeegee to remove the water from your shower walls, floors and benches, after you've showered.
Use vinegar, Mr. Clean, CLR, Vim, Easy Off, Windex, Magic Erasers, Bleach, or any other harsh cleaning chemicals on your natural stone.
Use SOS, Scotch-Bright or other scouring pads on your natural stone.
Let your stone come in contact with anything acidic.