Ring on the counter

There was a  ring on my granite countertop last night.  It was left by a coffee cup.  No matter how many times I wiped over it, it was still there.  But it seemed to fade just a bit.  Then I remembered that this is stone and surface marks often disappear after a good rain.  So I put a wet dishrag over the area overnight.  Voila - no ring this morning.  Now I have to remember to remove all ring makers before they have a chance to leave their mark.