Tarnish is a thin layer of corrosion that can form on the surface of gold. It is caused by a reaction between the gold and oxygen in the air. Tarnish can make gold look dull and discoloured. There are a few different ways to untarnish gold, including using a commercial gold cleaner, using a homemade solution, or using an ultrasonic cleaner.
Commercial gold cleaners are available at most hardware stores. They are typically made with a mild acid, such as hydrochloric acid or nitric acid. The acid will dissolve the tarnish and restore the gold to its original shine. However, it is important to follow the directions on the cleaner carefully, as using too much acid can damage the gold.
