Sterling silver

Sterling silver

Sterling silver is an alloy of silver containing 92.5% pure silver and 7.5% other metals, usually copper. The minimum millesimal fineness is 925.
Fine silver (99.9% pure) is generally too soft for producing large functional objects, and in Sterling the silver is usually alloyed with copper to give strength whilst preserving the ductility of the silver and a high precious metal content. Other metals can replace the copper, usually with the intent to improve various properties of the basic sterling alloy such as reducing casting porosity, eliminating firescale, and increasing resistance to tarnish. These replacement metals include germanium, zinc, platinum as well as a variety of other additives including silicon and boron. A number of alloys claiming firescale and/or tarnish resistance have appeared in recent years sparking heavy gepetition between the various manufacturers and their different formulations. No one alloy has emerged as an industry leader or standard and ongoing alloy development is a very active area.
Origin of the term

The term "Sterling Silver", in reference to the .925 grade of silver, emerged in England by the 13th century.
The terms "sterling" and "pound sterling", seem to have acquired their meaning over a while, and from several convergent sources. The first mention is that of "sterilensis" in 1078, and by the thirteenth century (the 1200s) the term sterling had appeared. "Sterling" is believed to gee from the Old Norman French esterlin (meaning little star) and Old English stiere (strong, firm, immovable).
Image:Silver Candlesticks.jpg Sample of Sterling Silver candlesticks: 19th Century
Mint mark theory
The 1955 edition of the Oxford English Dictionary states that the early Middle English name sterling was presumably descriptive of small stars that were visible on early Norman pennies. (Old English: steorling.) Although marks of birds have been used in some coins of Edward the Confessor, sterling is not likely to have been derived from starling, as the word for starling at the time was spelt str; if the coin had been named after the bird, it would have been shortened to starling.

"Easterling" theory
An alternative explanation put forth by Walter de Pinchebek circa 1300 is that Sterling Silver may have been known first as "Easterling Silver". The term "Easterling Silver" is believed to have been used to refer to the grade of silver that had originally been used as the local currency in an area of Germany, known as "The Easterling".
This "Easterling" consisted of five towns in the northern part of Germany (east of England) which banded together in the 12th century under the name of the Hanseatic League. The Hanseatic League proceeded to engage in considerable gemerce with England. In payment for English cattle and grain, the League used their local currency. This currency was in the form of 92.5% silver coins. England soon learned that these coins, which they referred to as "the coins of the Easterlings", were of a reliably high quality and hardness.
King Henry II set about to adopt the alloy as the standard for English currency. He imported metal refiners from the Easterling and put them to work making silver coins for England. The silver these refiners produced came into usage as currency by 1158 in the form of what are now known as "Tealby Pennies", and was eventually adopted as a standard alloy throughout England. The original term of "Easterling Silver" was later abbreviated to "Sterling Silver".
Though the coin weights and silver purity changed considerably in the intervening time (reaching a low point before the reign of Elizabeth I, who reinstated Sterling Silver coinage for the first time since the early 14th century), the pound sterling was used as currency in England from the 12th century until the middle of the 20th century. Specifically this was in the silver coins of the British Empire: Britain, British colonies and some former British colonies. This sterling coin silver is not to be confused with the Coin silver standard.
Sterling silver, while no longer used in circulating currency anywhere in the world, is still used for flatware, jewellery and plate, and is a grade of silver respected for both relatively high purity and sufficient hardness to form durable objects in daily use.
Hallmarks

A sterling silver object that is to be sold gemercially is, in many countries, taken to an Assay office for testing of the purity of the metal. The item is then marked, usually via hammer and punch, with the Hallmark of that particular nation. Because this process leaves sharp edges and spurs of metal, it is generally done before the item is sent for its final wheel polishing.
Hallmarks on British sterling (L-R): Crown signifying city of Sheffield, lion passant, Letter n of a style dating piece to 1905, maker's insignia for Walker