I don't know how it happened or when it happened but one day when I looked down at my kitchen sink faucet there was grime and hard water deposits that had accumulated from the past 10 years! One day there was nothing and the next day bam it was there! It was disgusting and I wanted it gone ASAP so I broke out the big guns and with ease was able to remove 10 years of hard water deposits in 15 mintues! Check out the before and after pictures and find out what tools you need to remove hardwater deposits like this. http://decoratedchaos.blogspot.com/2013/04/reviving-old-kitchen-sink-faucet.html
Start by saturating the entire area with a 60-40 percent mixture of white vinegar and water. Spray the area liberally with a spray bottle and let the mixture sit for a few minutes. This will help loosen everything up.
Then take an old handy dandy toothbrush and start scrubbing the water deposits. The gunk and hard water deposits will start to break off in little chunks. Then rinse with steaming hot water.
Now that you have cleaned off the top layer, grab a scouring pad to get the stubborn spots. Just moisten the pad with a little hot water and begin scrubbing the crevices where the remaining water deposits are.
You can see the blue "soap" from the scouring pad where I had to scrub a little harder than the toothbrush would allow.
Now give it one final rinse with hot water and use your dry eraser to clean off smudges. This step kind of "polishes" it off but is not necessary if you don't have any minor surface level scuffs.
One final rinse and a wipe down with a paper towel and you are done my friend! And no harmful chemicals were used which is a bonus!