I have granite counter tops in my kitchen and wonder if I haven't messed one of them up.

I had a bottle of dish detergent sitting behind the sink, and it trapped water beneath it for several days. When I moved it, the granite was dark and discolored where the bottle had been. Over the next week or so the darkness faded considerably, and today looks like the photograph below.

If I leave it alone, will the discoloration gradually fade away completely? Is it caused by moisture actually impregnating the surface of the granite? If it doesn't go away is there any remedy? And is there anything I should have done (other than not leave a wet bottle sitting there) to prevent this?

tanstaafl.