A piece of metal can be silver-plated to get the feeling of sterling silver. This is done to increase the life of the object and improve its aesthetic beauty. When buying, you should take care to check if the piece of metal is sterling silver or silver-plated. There are many ways to check for silver plating.
Check for symbols on the piece of metal, such as "EP," "EPNS" or "Silver on Copper." EP stands for electroplated and EPNS stands for electroplated nickel silver. These symbols denote the piece of metal has silver plating.
If the piece of metal is flat like a coin, observe it under a magnifying glass. Silver plating is sometimes not complete. There could be crevices or edges where the silver plating didn't completely fill or is not uniform. This can be seen under a magnifying glass.
Use a silver test kit. Such a kit is available at any hobby store or can be bought online. Scrape a few shavings of the metal onto a stone.
Place a drop of the acid provided in the kit. The acid is normally nitric acid.
Check the color of the metal after few minutes. The waiting period and the color chart will be provided in the kit. Normally, if the metal is pure silver, it will turn bright red. If there is contamination, it will turn to colors such as dark red, brown and green. Some kits might also check if the metal dissolves in the acid after a few minutes. If the metal does not dissolve, it is pure silver. If it dissolves, it is silver-plated.