Old coins can become oxidized and grimy with age. This can make it hard to see the markings on the coins. Even newer coins can quickly become dirty and grimy, especially if they have been found in the ground where the elements have wreaked havoc on their appearance. A few simple household ingredients are all that is needed to clean them up. Once you make the coins shiny, they are easier to study and they are more attractive to display.
Gold and Silver coins
Dip silver and gold coins into water, then coat them in a layer of baking soda.
Scrub the coins with an old toothbrush or a stiff-bristled nail brush to remove the dirt and tarnish. You may need to wet them and coat in baking soda multiple times.
Rinse away the baking soda in water and buff dry with a soft cloth.
Fill a small container with household vinegar. Place the pennies or other copper coins into a container.
Place the lid on the container securely and shake it for 5 to 10 minutes. Allow the coins to sit in the solution overnight.
Rinse under running water until it runs clean. Buff dry with a soft cloth to bring out the maximum shine.