The sterling silver standard has a minimum millesimal fineness of 925. Sterling is an alloy of silver containing 92.5% pure silver and 7.5% other metals, usually copper.

Origin of the alloy metal

Although there is much confusion over the origin of the word "sterling", there is general agreement that the sterling alloy originated in what is now continental Europe, and was being used for commerce as early as the 12th century in the area of what is now northern Germany.

Origin of the word "sterling", used to refer to the silver alloy

The word "sterling", used in reference to the 0.925 grade of silver, emerged in England by the 13th century. The terms "sterling" and "pound sterling" acquired their meaning in more than a century, and from convergent sources. There are three possible origins for the word "sterling". Two originate from 12th and 13th century coinage, and one is generally discounted. The word could have derived from the Old English word "stiere", meaning "strong, firm, immovable".

Starling theory, discounted

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 stær. If the coin had been named after the bird, it would have been called starling.

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.)

"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" area consisted of five towns in northern Germany that banded together in the 12th century under the name Hanseatic League. The Hanseatic League proceeded to engage in considerable commerce 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 recruited 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 name "Easterling Silver" later became known as simply "sterling silver".

The original English silver penny was 22½ troy grains of fine silver (as pure as can readily be made). 22½ troy grains is equivalent to 30 so called tower grains or one tower pennyweight. When Henry II reformed the coinage, he based the new coinage on the then international standard of the troy pound rather than the pre-conquest English standard of the tower pound. A troy pennyweight is 24 troy grains. To maintain the same amount of silver (and thus the same value) in a coin that weighed more required less silver. It required that the alloy be only 92½% pure.

Though coin weights and silver purity varied considerably (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 coin silver.

Sterling silver, no longer used in circulating currency, 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.

A century of dining regalia: the silver craze of 1840 to 1940

The height of the silver craze was during the 50-year period from 1870 to 1920. Flatware lines during this period sometimes included up to 100 different types of pieces. In conjunction with this, the dinner went from three courses to sometimes ten or more. There was a soup course, a salad course, a fruit course, a cheese course, an antipasto course, a fish course, the main course and a pastry or dessert course.

Individual eating implements often included forks (dinner fork, place fork, salad fork, pastry fork, shrimp or cocktail fork), spoons (teaspoon, coffee spoon, demitasse spoon, bouillon spoon, gumbo soup spoon, iced tea spoon) and knives (dinner knife, place knife, butter spreader, fruit knife, cheese knife). This was especially true during the Victorian time period, when etiquette dictated that nothing should be touched with one's fingers.

Serving pieces were often elaborately decorated and pierced and embellished with ivory, and could include any or all of the following: carving knife and fork, salad knife and fork, cold meat fork, punch ladle, soup ladle, gravy ladle, casserole serving spoon, berry spoon, lasagna server, macaroni server, asparagus server, cucumber server, tomato server, olive spoon, cheese scoop, fish knife and fork, pastry server, petit four server, cake knife, bon bon spoon, sugar sifter or caster and crumb remover with brush.

Flatware sets were often accompanied by tea services, hot water pots, chocolate pots, trays and salvers, goblets, demitasse cups and saucers, liqueur cups, bouillon cups, egg cups, sterling plates, napkin rings, water and wine pitchers and coasters, candelabra and even elaborate centerpieces.

In fact, the craze with sterling even extended to business (sterling page clips, mechanical pencils, letter openers, calling card boxes, cigarette cases), to the boudoir (sterling dresser trays, mirrors, hair and suit brushes, pill bottles, manicure sets, shoehorns, perfume bottles, powder bottles, hair clips) and even to children (cups, flatware, rattles, christening sets).

A number of factors converged to make sterling fall out of favor around the time of World War II. The cost of labor rose (sterling pieces were all still mostly hand-made, with only the basics being done by machine). Only the wealthy could afford the large number of servants required for fancy dining with ten courses. And changes in aesthetics resulted in people desiring simpler dinnerware that was easier to clean.

Hallmarks

Over the years, most countries in the world have developed their own systems of hallmarking silver. The purpose of hallmark application is manifold:

• To indicate the purity of the silver alloy used in the manufacture or hand-crafting of the piece.

• To identify the silversmith or company that made the piece.

• To note the date and/or location of the manufacture.

Miscellaneous

In addition to the uses of sterling silver mentioned above, there are some little known uses of sterling:

• Medical instruments: Evidence of silver and/or silver-alloy surgical and medical instruments has been found in civilisations as early as Ur, Hellenistic-era Egypt and Rome, and their use continued until largely replaced in Western countries in the mid to late 20th century by cheaper, disposable plastic items. Its natural malleability is an obvious physical advantage, but it also exhibits medically-specific utility, including the fact that it is naturally aseptic, and, in respect of modern medical practices, it is resistant to antiseptics, heat sterilisation and body fluids.

• Musical instruments: Due to sterling silver having a very special characteristic in sound resonance, some brasswind instrument manufacturers use 92.5% sterling silver as the material for making their instruments, including the flute and saxophones. For example, some leading saxophone manufactuers such as Selmer and Yanagisawa have crafted some of their saxophones from sterling silver, which they believe will make the instruments more resonant and colorful in timbre.

Tarnish and corrosion

As the purity of the silver decreases, the problem of corrosion or tarnishing increases.

Chemically, silver is not very reactive — it does not react with oxygen or water at ordinary temperatures, so does not easily form a silver oxide. However, the other metal in the alloy, usually copper, may react with oxygen in the air.

The black silver sulfide (Ag₂S) is among the most insoluble salts in aqueous solution, a property that is exploited for separating silver ions from other positive ions.

Sodium chloride (NaCl) or common table salt is known to corrode silver-copper alloy, typically seen in silver salt shakers where corrosion appears around the holes in the top.