When people ask me if making jewelry is boring, I tell them that there is never a dull moment. I believe in using non-toxic methods in my work, many of the techniques I use are not common practice in big industry. I use science daily in my work. Especially when restoring or adapting vintage jewelry. One of the most challenging issues in working with older silver is removing tarnish without removing a delicate finish or some of the silver. Oxidation isn’t like rust. It doesn’t eat away at the metal, it is a chemical reaction that forms on the surface of the metal. So, you don't need to rub or polish off a layer of silver to remove the tarnish.
Since sulfur bonds to both silver and aluminum, but the bonds are stronger to aluminum than to silver we are going to use aluminum to pull the sulfur away from the sterling, and we will use chemical bonding, hydrogen bonding, to do the heavy lifting for us.
You will need so basic kitchen items to transfer the sulfur from the silver to water and aluminum, making hydrogen sulfide aluminum sulfide.
Because we are using water, and the chemical makeup of water is H2O (hydrogen and oxygen), most of the sulfur will be lost in the form of air bubbles during the process. Hydrogen produces some of the strongest chemical bonds there are. You will be able to smell hydrogen sulfide. It smells like rotten eggs, because it is the same chemical you smell when cooking eggs, sulfur.
Very Important! Make sure you use an exhaust fan over the stove to keep the smell to a minimum or opening a window for ventilation. We will only be creating a very small amount of hydrogen sulfide. Even though it is non-toxic, you don't want to make your kitchen smell like cooked eggs. The body actually produces hydrogen sulfide by specific enzymes, see references listed at the end of this article.
Another really great thing about this process is if the original finish was matte it will stay matte and if it was shiny it will be shiny, unlike using an anti-tarnishing cloth or polishing paste that will remove some of the metal and make everything shiny.
Silver Sulfide (your non-gemstone tarnished jewelry)
Warning: Don't use this method with gemstone jewelry. Gemstones can crack if they are rapidly heated or cooled, and may even change color.
Aluminum (AKA tin foil is actually made from aluminum and not tin.)
Baking Soda or Salt
- Gently wash your jewelry, removing body oils that may be present on the surface. I like using dish soaps that don’t pollute our water supply with phosphates, but any dish soap will work.
- Use a small steel pot, not an aluminum pot, line the bottom with aluminum foil, add a heaping serving spoon of baking soda and about two inches of water.
- Boil the water to melt the baking soda or salt and remove it from the heat. You don’t have to boiling water with your jewelry.
- Add your tarnished jewelry. I use wood bamboo cooking tongs to gently set it in the pan because I don’t want to scratch it. Let it soak for about 10 to 15 minutes.
- I then take out each piece, let it cool on a towel and then rinse it off in clean water.
- pat dry it with a soft cloth that won't scratch your jewelry.
You can use a soft cloth and extra soft toothbrush to remove anything that remains in the nooks and carnies. Don’t try to scrub it off, you will remove a layer of silver. If it didn’t work check to make sure you followed all the steps. Did you forget the baking soda or salt?