Silver is a precious metal that has been used in jewelry and other items since 4000 B.C. Its beauty and malleability make it especially popular in jewelry. But due to its softness, silversmiths usually bond it with other metals such as lead, copper or zinc to give it more strength, especially for silverware. Markings on genuine silver pieces show the true silver content. Silver plating lays only a thin plating of silver over a cheaper base metal, and this is a familiar ploy for counterfeiters. Several tests can verify real silverware and flatware.
Check your silverware with a magnifying glass for silver content markings. Sterling silver contains 92.5 percent silver and is often marked “925,” "S925," "SS," “Sterling” or “Ster.” Pieces with less silver content may be marked “800,” meaning 80 percent silver and 20 percent alloy, and their value is accordingly lower. Be aware that counterfeiters may stamp anything onto their products.
Rub a soft white cloth over the silverware, then check for black marks on the cloth. Real sterling silver oxidizes, tarnishing with exposure to the air, so the cloth should have some black tarnish on it. If the silver is plated with platinum, this method won't work.
Smell the silver. A coppery or brass odor means there is too much metal alloy in the piece for it to be real silver.
Use a strong rare earth magnet. The magnet should be strong enough that it takes two hands to separate two of them. Even though sterling silver has some alloy in it, real silver will only have a slight pull on a strong magnet. If your rare metal--whether it's silver, gold or platinum--sticks to the magnet, it's not real.
Examine your silverware carefully. If the silver seems to be wearing off, it could be silver plate, which is not a good material for dinnerware that sees heavy use. If the silver looks like paint, it probably is. A simple scratch test with a metal file can verify this.
Pour a dab of French's yellow mustard on your silverware. Heat the mustard drop with a lighter. The high sulfur content in the mustard reacts with silver to create a black silver sulfide stain. Fake silver will not turn black. Clean off the black stain afterward with white vinegar and a soft cloth.
Ask a jeweler to test your silver with nitric acid. He will file a mark in a discreet spot and pour on a bit of nitric acid, which is a dangerous chemical. If everything stays creamy white, the piece is silver. If there are any dark green spots, especially in the filed area, the piece is not real silver. Silver plating will turn creamy white, but the filed area will turn green. You will not be able to restore the area where the piece turned dark.
Do not use nitric acid at home.