Things You'll Need
Instructions
Check to see that the necklace is indeed silver by searching for a hallmark. This will probably be next to the clasp, although some high-quality pieces also have stamps on individual links. In the United States, the legal standard for silver is 925 parts per thousand, so look for the impressed number "925," or the words "Sterling" or "Sterling Silver."
Weigh the necklace on a set of scales and make a note of the weight.
Undo the clasp, lay the necklace out straight and measure it from end to end with a tape measure or ruler.
Search for similar necklaces on Internet auction sites. Exactly how you do this will depend on the site, but the purpose is to enter the key search term -- "silver necklace" -- in addition to the weight and length. Most online auction sites have an advanced-search option that will accept these pieces of information. Once you've found a silver necklace the same weight and length as your own -- or the closest thing to it -- follow it using the site's tracking tool. Its final selling price will give you a very good idea of what your own necklace is worth.