White Cloudy Stain

I recently purchased a granite countertop (verde fire color). My husband put
a towel on the countertop to dry the dishes: we are currently remodeling and
do not have a dishwasher. He left the towel there for a couple of days while
putting wet dishes there. When I remove the towel it left a light cloudy
stain on the countertop. I was thinking it was only water and it will dry
off, but it is more than a week now and the stain is still there. What can I
do? Is it really water stain, because it is not darker but instead a lighter
gray area and cloudy. I look up at internet and nobody seems to have this
problem with water. The countertop is located on an area that we never use
(otherwise than stupidly put a damp towel over!!) and the cooking area is
not there so it cannot be oil or other things. Plus, we are as I said
remodeling, so basically we only boil water in the kitchen, so what can I
try? Thanks a lot.

Julie