Thursday, June 2, 2011
This means that sterling silver is usually used for silver jewelry. Sterling silver has about 7.5 percent copper mixed with the silver. In the US silver jewelry must not be described as silver, solid silver, sterling silver, sterling, or with the abbreviation Ster unless it contains 92.5 percent pure silver per the US Federal Trade Commission (FTC).
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. This is used mostly in the manufacture of silver tableware. The alloy used in Britannia is larger as the silver needs to be much more durable and hardwearing.
Although copper is ideal for giving silver that hardness required it does tend to tarnish. Tarnishing is the result of the silver and copper coming into contact with the atmosphere, gases and the natural oils of the body with which it is in contact.
Sterling silver jewelry is very often plated with a thin coat of .999 fine silver to give the item a shiny finish in a process called flashing. Sometimes a very thin layer of rhodium is used instead in some cases. The only problem with a rhodium coating is that as it wears away over time you will begin to see 'patches' as the silver underneath eventually becomes exposed. There is no way to prevent this and the only recourse is to get the piece replated with rhodium again. Rhodium is subject to scratching also and as it does not adhere to stones, makes jewelry with stones difficult and expensive.
It is important to look after your silver jewelry. Keeping it stored in cloth out of the light and away from moisture and other jewelry items is a good idea. Silver can be scratched so should be kept separate from other jewelry especially those with stone such as diamonds.
You can clean your silver jewelry with an old soft toothbrush but do not use toothpaste. It is abrasive and can leave unsightly scratches. You can buy proper polishing cloths from as jewellers or supermarket for polishing silver.
Finally silver that you wear daily often develops a patina, a green or brown film on the surface produced by oxidation over a long period. If you like this do nothing of course. Otherwise you can use a polishing cloth to remove this and restore your silver jewelry to its original pristine appearance.
Next to gold, silver jewelry is perhaps the most popular and, well looked after, will provide many years of pleasure.