Natural stone bears nature's many complexities and shows large variations in its absorption, density and hardness. These have an important impact on how to protect and preserve the appearance and beauty of the stone.
Due to these natural variations many stone surfaces can easily lose their appealing aesthetic qualities due to damage resulting from the everyday wear of...foot-traffic (floors), spills, harsh cleaners and the weathering elements.
The fact that some stones are absorbent and have mineral compositions that can react in strange ways to conventional cleaners, makes the proper selection of cleaners very important for successfully maintaining stone on a daily bases.
Many of the commercial conventional products that are labeled "Neutral", "All-Purpose" cleaners can have a pH ranging from slightly acidic 6 to a alkaline base of 8 - 10. The chemical reactions of these cleaners are gradual; they can eventually dull the natural polish of the stone and discolor it over time. It is generally not recommended using these all-purpose cleaners on stone surfaces.
Numerous specialty stone care products have been formulated to effectively solve the specific cleaning problems related to the absorbent and mineral characteristics of stone.
Also, due to absorbent nature of some varieties of stone, they can absorb liquids and oils, causing stains, discolorations or irreversible mineralogical chemical changes in the stone. These processes are greatly minimized by having the stone treated with a penetrating (or impregnating) sealer
These sealers penetrate below the surface into the micro-pore structure, lining them and interrupting the natural migration of moisture or oil into the stone, making the stone surface easier to clean; and in exterior installations provides protections from the adverse affects of the natural weathering processes.
If the stone will be used where foods and oils will be present, it is recommended to treated these areas with a oil repellent and in general purpose areas with a water repellent.
NOTE : Penetrating sealers will not protect acid-sensitive (calcium-based) stones like marble & limestone from etching, however, they can minimize its damaging affects by keeping the acid at the surface producing superficial etches that are easier and less costly to remove.