Jewellery and silverware are traditionally made from sterling silver (standard silver), an alloy of 92.5% silver with 7.5% copper. In the US, only an alloy consisting of at least 90.0% fine silver can be marketed as “silver” (thus frequently stamped 900). Sterling silver (stamped 925) is harder than pure silver, and has a lower melting point (893°C) than either pure silver or pure copper. Britannia silver is an alternative, hallmark-quality standard containing 95.8% silver, often used to make silver tableware and wrought plate. With the addition of germanium, the patented modified alloy Argentium Sterling silver is formed, with improved properties, including resistance to fire scale.
Sterling silver jewellery is often plated with a thin coat of .999 fine silver to give the item a shiny finish. This process is called “flashing”. Silver jewelry can also be plated with rhodium (for a bright, shiny look) or gold (to produce silver gilt).
Silver is a constituent of almost all colored carat gold alloys and carat gold solders, giving the alloys paler color and greater hardness. White 9 carat gold contains 62.5% silver and 37.5% gold, while 22 carat gold contains a minimum of 91.7% gold and 8.3% silver or copper or other metals.
Some silver hallmarks:
All silver jewellery is stamped with a hallmark for Identification.