I've searched the internet high and low for a solution to this and for the life of me can't figure it out. I'm hoping perhaps someone here can. Let me explain.
I have a stainless steel sink in my kitchen. Recently, a bowl was left there overnight and when it was removed, a white half-circle stain/discoloration was left behind (see images).


I have tried dish soap, comet (non-scratch formula for the house), baking soda, CLR Bath & Kitchen Multi-Surface Cleaner, "Steel for Real" Stainless Steel Polish... nothing is making this stain go away. The rest of my sink is gorgeous due to all these cleaning efforts, but the stain remains. I'm not even making a dent so far as I can tell.
Anything else I should try?

