Tarnish is the product of a chemical reaction between a metal and a non-metal compound such as oxygen or sulfur dioxide. A thin layer of corrosion forms over the metal, which mars its shine.
What metals can tarnish?
Your 24 karat gold (pure gold not mixed with other metals) and platinum will not tarnish, but pretty much all other metals will, including less-than-24 karat gold, silver, copper, brass, aluminum and magnesium.
How can I prevent tarnish?
When jewelry is made of metals that can tarnish, you should be careful about how you store it in order to prevent contact with a substance that can cause tarnish. Leaving a piece exposed to the air will cause tarnish due to exposure to oxygen, so these pieces should be stored in a box or pouch. Be sure that your storage option is designed for the purpose and does not use sulfur in the fabric, glue, paper or threads, as sulfur compounds will cause tarnish to develop.
Anti-tarnish fabric is used to make pouches and to line jewelry boxes; anti-tarnish strips can be added to your storage to increase protection. Anti-tarnish cloths and papers both contain substances that absorb or attract the tarnish-causing compound before it comes into contact with the metal. This process prevents tarnish from developing but does not remove existing tarnish.
Can I buy jewelry that won’t tarnish?
Gold and platinum jewelry will not tarnish, but is also more expensive. Gold or rhodium plating on silver is one option to prevent tarnish. There are also tarnish-preventing chemicals that can be applied to the metal to protect it for a period of time. While these options impede tarnish, they do not prevent it permanently. Plating and chemicals will wear away, eventually exposing the underlying metal to tarnish-causing agents. Talk to your jeweler about the best options for your needs.
How do I remove tarnish?
Tarnish can be removed through polishing with a professional polishing cloth or using a tarnish-removing formula. Ask your jeweler to recommend a suitable formula which is designed for the purpose.