Cleaning marble in the shower
As many of you already know, most cleaning products purchased at your local grocery are not geared for cleaning stone. Most have harsh abrasives and bleach, which is damaging to natural stone. There are many lines of stone cleaners that can be purchased from your local stone retailer to deal with soap scum and such or look for ph neutral cleaners, which you can sometimes find at your local grocery. You may also consider using a diluted mixture of Downy and water described here: http://www.diynetwork.com/diy/lv_household_tips/article/0,2041,DIY_14119_2275101,00.html
In addition. maintenance is the key to preventing problems in a marble shower. You should keep a squeegee nearby (one with no metal parts which could damage the stone) and dry the walls daily after your shower. This will reduce the potential of mold and mildew build up and mineral deposits. Today, there are grouts on the market which are mildew proof. You will pay a hefty premium for this grout but it will represent only a tiny fraction of what you paid for that beautiful marble. See without water, it is very hard for mildew to grow! If you do encounter mold and mildew in the shower,
Polished marble in the bathroom has become dull?
Many ask how to polish marble to bring back the shine of when it was first installed. If your polished marble is now dull it could be related to a variety of reasons. Sometimes you just need to remove the soap scum, which can be done with professional stone cleaners. Perhaps mineral deposits have built up and etched the stone or general use has dulled the surface. You can first try a color enhancing sealer with a gloss. If this does not bring back the shine then you may need to have a professional repolish the marble.
Professional re-polishing involves the use of a polishing machine which grinds and sands down the surface. Although, you see the polished marble in hotels, malls, and office buildings, keep in mind that alot of maintenance goes into keeping those surfaces shiny and new looking.