Surface staining is where a chemical has left a coloured mark on the surface. This stain/mark may be sitting on the surface or be penetrated into the stone depending on how porous the stone is. Sealers will buy you some time to remove the offending chemical before the surface is permanently stained. This will vary depending on the sealer, stone and chemical involved, some chemicals can stain in minutes.

Etching is a totally different problem. A lot of problems that are associated with a majority of stone surfaces are that they are actually etched not stained.

Marble and Limestone are composed of calcite which is highly sensitive to acids spills which corrodes the surface (etching) thus damaging the polished or honed finish. Even acids in water can affect some stones leaving a white ring from a glass left on a bench top.

Etching can appear as a blotch or dull spot, have a lighter coloured (white) bleached appearance, feel rougher, or feel and look as if the surface is pitted. Severe etching can lead to the surface crumbling and flaking.

Some stones like marble and limestone can also be porous and are susceptible to both staining and etching at the same time.

Some stones such as sandstone and basalts are not receptive to a high-honed or polished finish due to their open grains.  This can make them more susceptible to staining and etching.

Last updated on April 13, 2012 by Lustre Ltd