Frequently Asked Question ... What is Sterling Silver?

In the course of my day I get a lot of email, and a fair amount of people want to know what sterling silver actually is. Today, sterling silver is the most common type of silver and the kind most people are familiar with.

Sterling silver is an alloy, which means it is a mixture of two or more metals. The primary reason silver is mixed with another metal is to harden it. Most sterling silver is a mixture of silver and copper. The proportion of metals by weight in the alloy determines the fineness or purity of the silver, as well as the name of the alloy. There are three commonly found silver metals found in the United States:

Pure silver is also called Fine silver. This is 999/1000 or 999 parts per 1000 pure. This is considered pure; the remaining .001 consists of (usually) traces of other metals. Fine silver jewelry is usually marked or stamped .999FS.

Pure silver is a soft metal. Unless it is very thick it can easily be bent by hand, and is easily scratched. Items made of fine silver need to be made with thicker sheet and wire to give them strength. By using sterling instead, thinner parts can be used because sterling is much more rigid when hardened than fine silver.

Sterling silver is always marked .925, which shows the amount of silver in the object. The same formula is used; this alloy is 925 parts per thousand silver and 75 parts per thousand other metal, usually copper. This can also be expressed as 92.5% silver and 7.5% other metal (copper) by weight.

The third commonly found type of silver in the U.S. is Coin Silver. Until 1964, United States coins 10¢ and larger were made of a silver alloy containing 90% silver and 10% copper by weight. A higher percentage of copper was used to make the silver harder and more durable so the high relief and details of the coins wouldn't wear away in circulation. Many of these coins are still held by collectors, and there are silversmiths who make coin jewelry out of them.

Silver jewelry is usually made with sterling silver because it is durable. Jewelry made with fine silver does have one advantage over sterling; it doesn't tarnish easily due to the absence of copper. Sterling silver tarnishes because the copper in it reacts with sulphur dioxide in our air. Sulphur dioxide is a common chemical compound found in everyday air pollution. It can come from natural sources like volcanic eruptions, and also man made sources like vehicle emissions and factories.

Sterling silver is a fabulous metal for jewelry making because it retains many of the properties that make fine silver attractive while gaining the benefit of increased durability. With minimal care - a cleaning and polishing when needed - sterling silver jewelry can last for many generations.

Robert Edwards is a jewelry designer and metalsmith in New York City with over 30 years experience in the jewelry trade, specialzing in handmade silver jewelry. This article may be reproduced as long as it contains this author's statement and all links remain intact. ©2009 Robert Edwards