How to remove rust and black circles from pan left in the sink?

I live in a very old apartment building on my college campus. I made muffins in a pan a few days ago. To keep food from sticking to the pan, I sat it in my white (what I believe to be ceramic) sink with water in it. Well, that was a mistake because now there is rust and black rings where the pan was sitting. Is there any cleaner I can buy that will get rid of the rust and black circles?
Answers

yimi

CLR or any one of a slew of chemicals.

Anonymous

Ajax or comet cleanser. It comes in a round can shaker and you put on a prewetted sink and sand off the stain...with a super fine abrasive.

Lib.rare.ian

Comet cleanser should work. Get the bottom of the sink wet. Liberally sprinkle Comet cleanser over the bottom of the sink, covering the stains. Keep the powder moist and let it sit for about 1/2 an hour. Cover it with damp paper towels if you have to. After it has soaked a while, start scrubbing the sink with the damp powdered cleanser using a nylon scrubbie or similar non-scratching tough scrubbing sponge. A lot of elbow grease and Comet should get rid of the stains. Repeat as necessary.

Henry

CLR or any one of a slew of chemicals.

Gino C

use old coffe grinds

ckngbbbls

any SOS pads will take that off.