Silver is a metal that is precious and beautiful but soft. Therefore silver is usually alloyed with copper to give it hardness. However too much copper means less silver and therefore less valuable. So in the Middle Ages in Europe the sterling silver standard was set for the maximum per cent of copper (or any metal other than silver) that could be alloyed into a silver piece and still allowing the silver to meet the standard. The standard was and has continued to be at least 92.5% silver. The word sterling is believed to come from an old word for star. Sterling silver has been used in coins, jewelry, and eating utensils (hence the term silver ware). Silver forks and spoons could only be afforded by the most wealthy people. Today sterling silver is often used in jewelry, but as for eating utensils it is mostly found in antiques.
The upper plates in the hand crafted earrings pictured above are made of sterling silver. They can be found on the Metal Jewelry Shaper web site.
Incidentally Rose (the Metal Jewelry Shaper) will be teaching classes in various metal jewelry making techniques at the Bead and boutique Arts show at the Concord Hilton hotel in Concord, California February 28 through March 2, 2014. See Metal Jewelry Classes for details.