About Sterling Silver
"Sterling silver" is an international designation defined as a metal alloy (blend) containing at least 92.5% silver. The most common sterling alloy is 92.5% silver and 7.5% copper. The addition of copper adds hardness to the metal. Silver jewelry advertised as "sterling" must meet that standard. In most cases, genuine sterling silver jewelry will be stamped ".925" which indicates its 92.5% silver content.
Fine silver, usually stamped ".999," is 99.9% silver. Since silver is a soft metal, fine silver is typically used only on heavier jewelry articles, such as cuff bracelets, where flexibility is important. When adjusting .999 silver bracelets and bangles to fit on your wrist, carefully manipulate the metal so that it doesn't lose its shape. The best way to clean and restore the finish of your .999 silver is with the use of a chemically treated jewelry polishing cloth.
Silver can oxidize when in contact with chemicals in the environment and air. This is not a defect, but a natural property of silver, and it can easily be restored to its original luster by polishing with a silver polishing cloth or paste. Articles plated with rhodium or gold are not subject to oxidation and should be cleaned with mild dish soap and a lint-free cloth.