What are the differences between an etch and a stain on your stone?

One of the most common calls we get is for problems with marble countertops and vanities.  Customers say I have all these “spots, or stains on my marble, what can I do?”
It is important to clarify the differences between a stain, and an etch mark.  A stain occurs when a pigmented product comes in contact with the stone and seeps into the open pores.  One way to prevent this is to seal the stone. Generally speaking, stains are darker than the stone.

Etches are generally lighter than the stone.  They are caused by an acidic, (solutions between 0 and 6 on the pH scale) coming into contact with the stone and actually eating away at the surface.  This often looks like spots or water marks. The only way to correct this is to contact a professional that can hone the surface with professional abrasives to remove the damage and re-polish to desired level of shine.  Although you can seal all surfaces, sealer will not protect against further etching.  You must be diligent about keeping all acidic product s off your marble surfaces.