Marble is a metamorphosed limestone composition. It started out as limestone which over many years in the earth’s crust has recrystallized due to heat and pressure. The original carbonate minerals and the fossils become coarse grains of calcite. Marble comes in a wide variety of colors, which is determined by its mineral composition when it is formed. This in turn is determined by what impurities are present in the limestone during the crystallization process. It is distinguished from other polished natural stones by its heavy veins and abundant graininess. The three categories it can be classified into are Dolomite, Magnesium or Calcite depending on the quantities of these minerals that it contains.
Restoration and Maintenance
A polished marble floor will scratch very easily compared to a harder stone like granite. Sand, which has a hardness rating of 7 on Moh’s Scale will scratch marble if it walked onto as most marble has a hardness rating of about 3.
The reflectivity after polishing marble is caused by natural crystals in the stone. When sediment and grit are walked, dragged or scraped across the stone, the crystals become damaged and the surface is not longer even, causing a loss of reflectivity and shine.
It is important to protect your marble with good barrier matting as a preventive step. Keeping indoor slippers to change into by the door is also recommended as outdoor dirt and grit can become trapped in the tread of the shoes. Taking these measures will help to prevent the loss of shine.
Marble can be extremely porous if it is honed rather than polished and so it is imperative that it is properly sealed with a penetrative sealer prior to usage. Polished marble does not necessarily need to be sealed due to something called the Beilby layer.
Any stone needs a well planned maintenance schedule in place to preserve it and to delay restoration procedures for as long as possible. One way to accomplish this is to follow a daily maintenance schedule. Daily maintenance should consist of dry dust mopping using a clean rayon mop. Regular damp mopping will also be required. This should be carried out using a quality PH neutral stone soap alternated with fresh water. It is important that soap residue not be allowed to build up on the surface of the stone. Residue from soap will reduce light reflectivity of the surface of the stone. When a soap is used multiple rinses will be required, frequently changing the rinse water. Spills should be cleaned up promptly to prevent staining or etching. Acid based chemicals use for other household cleaning should never be used on marble as they can damage the surface of marble and other calcite stones on contact. Similar damage from acid based foods and drinks can be avoided if not left to dwell. Regular professional natural stone floor maintenance will be required to maintain a good shine on the stone. This will involve the use of polishing powders. Any staining which has occurred may be removed using a poultice powders and other specialist methods prior to polishing.
At some point in time a full marble restoration service will be required. This will be due to the large amount of cracking, deep scratching, unsightly lippage, moving tiles, grout damage, high traffic patterns, problem staining or any other defect which cannot be remedied by polishing marble alone. Resurfacing of the marble will require a diamond abrasive procedure referred to in the industry as diamond grinding. This is carried out after any epoxy repair work. The marble is then polished or left honed and then re-sealed.