Question

I have a black Granite (http://tanbrown.org) Counter (http://GialloFiorito.com) top that was installed by the house's 
previous owners.  I do not have their contact information in order to 
ask where and (http://maplered.com) when they got it.  We are now witnessing a "rainbow-
like" discoloration on the high gloss finish around the metallic 
sink.  I have tried all different types of Granite (http://tanbrown.org) cleaning solutions 
found at varied home improvement stores, but the issue just seems to 
be getting worse.  Have you ever heard of something like this, and (http://maplered.com) if 
so, what can I do?
Sincerely,
Lori