The difference between silver and plated silver is a matter of value. Plated silver means that the object has a very thin coat of silver applied. This type of silver has little value, with the silver coating generally wearing off the item in under 20 years time. Pure silver is not often used because it is such a soft metal, and is often quite costly. Sterling silver is 92.5 percent pure silver, often mixed with 7.5 percent copper for hardness.
Examine the item in question. Markings of "STERLING," ".925" or "925/1000" will identify a piece as being sterling silver.
Locate any marking of "EP," "AI," "XII," the numbers "4, 6, 8, 9 or 12," "Triple" or "Heavy Plate." These markings identify an item as plated silver.
Place a drop of acid in an inconspicuous place on the item in question. If the acid drop changes to any other color other than cream it is a plated material. Thoroughly clean the acid from the item to keep it from further damaging the silver or plating.
When the quality of an item is in question, take the item to a certified silver jeweler, they will be able to test or identify the authenticity of the silver in question.