About Marble: History, Composition and Uses
Marble is a metamorphosed limestone composition. This basically means that 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 different colours. The colour of the marble is determined by it’s mineral composition when it is formed. This in turn is determined by what impurities are present in the limestone during the crystallization process.
Colours vary from the well known pure white calcite varieties to less known varieties containing hematite which are reddish. Marble has a hardness rating of 2.5 – 5 on Moh’s scale. It is distinguished from other polished natural stone by it’s 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.
- Statuary & carving: Usually pure calcite marble which is translucent
- Building stone, exterior cladding & flooring: Usually coloured blocks or slabs
- Soap abrasives: crushed or finely ground
Restoration and Maintenance:
It is important to understand the stone maintenance cycle in order to properly maintain the beauty and lustre of your natural stone installation.
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 is walked onto it as most marble has a hardness rating of about 3. The reflectivity on a polished marble floor 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 no longer even causing a loss in reflectivity and shine. Therefore good barrier matting is essential as a preventive step. Keeping indoor slippers to change into by the door is also recommended as outdoor grit can often get trapped in the treads of your shoes. Taking the above measures will help to prevent loss of shine however another important factor to consider is the possibility of staining. Marble can be a very porous stone if it is honed rather than polished and so it is important that it is properly sealed with a penetrative sealer prior to usage.
Any stone needs a well planned maintenance schedule in place to preserve it and to delay restoration procedures for as long as possible.
Daily maintenance will consist of dry dust mopping using a clean rayon mop. Regular damp mopping will also be required. This must be carried out using a good quality stone soap alternated with just freshwater. It is important that soap residue doesn’t build up on the surface of the stone. Spills should be wiped promptly to prevent staining or etching. Acid-based chemicals used for household cleaning can damage the surface of marble and other calcite stones on contact. Similar damage from acid-based foods and beverages can be avoided if not left to dwell.
Professional regular maintenance will be required to maintain a good shine on the stone. This will involve the use of polishing powders or vitrification chemicals. Any staining which has occurred can also be removed using poultice powders and other specialist methods prior to polishing.
At some point in time, the marble will require complete restoration. This will be due to large amounts of cracking, deep scratching, unsightly lippage, moving tiles, grout damage, irremovable traffic patterns, problem staining or any other defect which cannot be remedied by polishing 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.
Our extensive experience in marble restoration will give you peace of mind when choosing a stone care professional. We offer a consultancy service to architects and interior designers and our reputation in the industry is unrivalled. Please see our testimonials page and feel free to contact us for free expert advice and a no-obligation survey.