What is the Difference Between a Stain And An Etch?
As a rule of thumb, a stain in natural stone will turn the stone darker and an etch will turn the stone lighter.
Liquids That Cause Stains
A stain is when a contaminant such as coffee, cooking oil, wine, rust and many other contaminants sit on a natural stone long enough and absorbs into the pores of the stone causing a stain or “darkening” of the affected areas. To repair a stain, there are many types of poultice products to draw out the stain depending on the type of stain it is.
How Etches Occur
An etch occurs when something acidic such as lemons, vinegar, carbonated beverages, and acid based cleaners sit on a natural stone long enough that it starts to corrode or “eat” away at the surface and will give a lighter or dull appearance. If the etch is bad enough, the affected area may even feel rough or not as smooth as the rest of the stone.
Etching is more common in marbles and calcium based stones, but “granite” can etch as well. True granites do not etch, however many stones are sold as granite but geologically are not; so it is important to know exactly what type of stone you do have.
Polishing powders can repair lighter etches on marbles and calcium based stones, but to repair deeper etches on marble or a “granite” may require the help of a stone profession.
Two Birds, One Stone
Many times you can get a stain and an etch at the same time. In this situation, always remove the stain first as some poultice products can cause etching and you don’t want to repair the etch twice. There are products to help prevent stains and etching.