When silver tarnishes, it is because the silver combines with tiny bits of sulfur in the air to form silver sulfide. Silver sulfide is black, and when it coats the silver it dulls the shine.

There are two ways to restore the shine. One is the way most of us know, which is to wipe off the silver sulfide (and a bit of the silver, too) with polish and a lot of rubbing. The other is to turn the silver sulfide back into silver again by getting rid of the sulfur – it’s actually EASIER than polishing, and won’t remove the silver!

Sulfur will combine with many metals, some of them more easily than with silver. One of these metals is aluminum. Chemically, what we will do is to cause the sulfur atoms to be transferred from the silver sulfide to the aluminum, making both aluminum sulfide and a shiny silver whatnot! In your high school chemistry class it looked like this: 3 Ag2S + 2 Al –> 6 Ag + Al2S3

But what we need for our purposes looks more like it came from Home Ec class:

Something silver and tarnished
A pot big enough to hold it
Enough water to fill the pot, in another pan
Aluminum foil
Oven mitts
Baking soda, 1 cup per gallon of water used

Line the bottom of the pan with aluminum foil. Put your silver on top of the aluminum foil (make sure they’re touching, because the small electrical current that flows between them during the chemical reaction is what makes it work). Heat the water to boiling and move it to the sink (use the oven mitts!). Stir in the baking soda – it may froth over, which is why you put the pan in the sink. Now pour this liquid into the aluminum-and-silver pot to completely cover the silver.

See? Isn’t that cool?

If the silver is very tarnished you may have to heat the water mixture again and re-treat several times; if not, all the tarnish should be removed within a few minutes.

Isn’t science fun?