Here is some information that I looked up on various websites:-The SILVER Test
How can you tell if an item that you have found is silver or not? Here's an easy way.
The only thing you need is a piece of tin foil (silver cooking foil). Get the item that you think is silver and place it on the tin foil. Now, SPIT on the item, this will not harm the item at all.
Cover the item tightly with the foil after you have spat on it. Leave it for 5-10 seconds, then open the foil. Bring it up to your nose and smell it as you open it. If it smells like rotten eggs then it's silver.
You will notice straight away as the smell is unmistakable and strong. Try this with something that you know is silver so that you can see it works.Simple test for silver
25 gm potassium dichromate
25 gm nitric acid
Silver = red or reddish brow colour
(Only oxide and grease free objects can be tested, one drop is sufficient, rinse well immediately!)Silver Testing
Metal items that are supposed to be silver may be tested first with a magnet. If the magnet is attracted, the item is not silver. To test a piece for silver content, place a drop of silver reagent on a notch in the metal. Pure silver will then turn bright red, while sterling will turn much darker red. Silver that is .800 will test brown, and an object that is only .500 silver will turn green.
I've never tried any of the above mentioned silver tests, but who knows, they may be helpful? Good Luck!