We have been seeing an increasing number of items come into the shop that have all the correct markings for sterling silver - they have "925" or "Sterling" stamped right into them, but examination of them has shown that they are NOT sterling silver.
All it takes to know if you are being sold a pig in a silver blanket is a magnet.
Silver will NOT be attracted to a magnet. It is non-ferrous. In order for something to be sold as "sterling silver" and/or "925" it must contain 925 (92.5%) parts per thousand pure silver with the remaining 75 parts (7.5%) being made up of various alloys that work well with silver.
When testing a chain or a bracelet - do NOT test the clasp because there is usually a small steel spring in the clasp mechanism - if you hold your magnet by the chain itself and the chain is attracted AT ALL to the magnet, then the product is not sterling silver. If a ring moves toward the magnet, it is not silver. The same holds true for a pendant or bracelet.