It is an alloy of silver containing 92.5% by mass of silver and 7.5% by mass of other metals, usually copper.
Usually, sterling silver has a purity of 92.5%, meaning that 7.5% of the alloy is made of copper or another metal (usually nickel or zinc). There is also the so-called coin silver, which is an alloy of lower purity: It usually contains 90% or less silver. Silver, Sterling Silver, and Tarnishing. Although sterling silver is more durable than pure silver, the additional metals in the alloy make sterling silver more prone to tarnishing. This happens because the copper, nickel, zinc or other mixtures in sterling silver may react with oxygen and other elements in the air. Sterling silver is an alloy of silver containing 92.5% by mass of silver and 7.5% by mass of other metals, usually copper. The sterling silver standard has a minimum millesimal fineness of 925. Fine silver, for example 99.9% pure silver, is generally too soft for producing functional objects; therefore, the silver is usually alloyed with copper to give it strength while preserving the ductility and appearance of the precious metal. Sterling silver is a popular metal for jewelry, silverware and decorations. Sterling silver is an alloy of silver that consists of 92.5% pure silver and 7.5% of other metal, usually copper. Fine silver (99.9% pure) typically is too soft for practical objects. Alloying with copper maintains the silvery color of the metal, while increasing its strength Sterling silver is often characterized as pure silver, when in fact it is a silver alloy. Pure silver, also called fine silver, is defined as 99.9% pure silver, but is too soft for most uses. Sterling contains 92.5% silver, with the remaining 7.5% being another metal, most often copper. On the other hand, sterling silver consists of approximately 92.5% silver, and the remaining 7.5% (or even more) is of other metals. Because of the high percentage of silver in ‘pure silver,’ it cannot be used to make those daily rough and tuff items. 1. Sterling silver is mainly an alloy of silver, consisting of nearly 92.5% fine silver and 7.5% other metals, like copper, which make it less expensive. Fine silver is composed of 99.9% pure silver, and it is a bit more expensive. That’s why it is used for making jewelry, and also in the photography industry .925 is the marking for sterling and means that the metal is 925 parts of 1000 pure silver. Sterling also comes in .999 but pieces made with this are rare as Silver is soft metal and anything greater than the standard of .925 causes problems with the craftsmanship. 5.  Sterling silver is a frequently misused term, especially on eBay. Some have the impression that any silver may be termed sterling however the word sterling applies only to an item which has a guranteed silver content certified as a minimum of 925 parts out of 1,000 parts. The remaining 75 parts are an alloy of copper, nickel, and perhaps other metals. Sterling Silver Price. The current price of Sterling Silver (anything) is $13.33 per Ounce (oz), or $0.47 Per Gram (g). Sterling silver is defined as 92.5% pure silver and is widely used in high end cutlery, jewelry, and pitchers. The other 7.5% is usually made of some other metal like copper.  In summary, there are two major differences between silver and sterling silver: 1. Sterling silver is mainly an alloy of silver, consisting of nearly 92.5% fine silver and 7.5% other metals, like copper, which make it less expensive. Fine silver is composed of 99.9% pure silver, and it is a bit more expensive. That’s why it is used for making jewelry, and also in the photography industry.
http://www.jewelrynotes.com/sterling-silver-vs-pure-silver-what-is-the-difference/ https://en.wikipedia.org/wiki/Sterling_silver http://chemistry.about.com/od/metalsalloys/a/Sterling-Silver.htm http://www.wisegeek.org/what-is-sterling-silver.htm http://www.differencebetween.net/object/difference-between-silver-and-sterling-silver/ http://www.ebay.com/gds/Sterling-Silver-Jewelry-What-is-Real-Silver-and-What-is-Not-/10000000177705458/g.html http://www.ebay.com/gds/Sterling-Silver-What-it-Is-and-is-Not-/10000000001262196/g.html http://cointrackers.com/blog/25/sterling-silver-prices/ http://www.differencebetween.net/object/difference-between-silver-and-sterling-silver/
what is sterling silver