Coin silver (900)

How to read it

The FTC’s jewelry guides keep the words coin and coin silver for metal of at least 900/1,000ths pure silver, and the National Gold and Silver Stamping Act says the same of anything marked coin or coin silver. The FTC’s consumer guide puts it as 90% pure silver. When the FTC revised its guides in 2018, it dropped the 925 threshold for the plain word silver but kept this one, because terms like coin silver likely denote specific purity levels, and coin silver contains less silver than sterling.

Also searched as: 900 silver, coin.

Coin or sterling?

Coin silver is a lower standard than sterling, which starts at 925 parts per thousand. In the Stamping Act, sterling and coin are the only silver words with fixed figures; any other silver mark is a number.

How much tolerance the word coin allows

The Stamping Act allows a divergence of four parts per thousand for silver marked coin, the same as for sterling. Assayed as one piece with its solder, the whole article may fall short of the marked fineness by no more than ten parts per thousand.

The word on plated goods

The Stamping Act bars the words sterling and coin from silver-plated and gold-plated articles, either alone or in conjunction with other words or marks. So under the Act, the word coin is a claim about the silver itself, not about a plating.

Where the word came from

The mark is found on American silver. Howard Pitcher Okie, writing in 1928, lists American makers who struck marks such as COIN and PURE COIN in rectangles beside their names. He also records Low, Ball & Company of Boston, around 1810 the largest importers of English silver, stamping Coin silver and their own firm’s name on English pieces that were already fully hallmarked, because hallmarks meant so little to buyers in America. Okie notes one American exception: Baltimore, which from 1814 set a minimum standard of 11 ounces of silver in the troy pound and appointed an assayer, until the office was abolished in 1830 and replaced by a law requiring silversmiths to stamp the quality of their wares.

Coin silver in Britain

The British story runs the other way. The Silver Society writes that until the end of the 17th century, silver coins and silver wares in England were all required to be sterling, and that in 1697 a higher standard, Britannia silver, was introduced for wares to stop them being made from melted coins. A 900 standard has no place in a British hallmark: the Hallmarking Act strikes silver at 800, 925, 958 or 999. The Act exempts actual coins, current or former, from hallmarking, which is a separate matter from the mark coin on a spoon or a ring.

Coin silver and the Convention

None of the finenesses recognised under the International Hallmarking Convention is 900 silver; the UK assay offices’ guidance lists 800, 925, 958 and 999.

Who stands behind a coin mark

The Stamping Act’s trademark rule, added in 1961, applies to any quality mark indicating silver, the word coin included: whoever applies it must also apply a registered trademark or their name, close to the mark and at least as large. The FTC’s guides list parts that are not considered in any assay of a silver product, among them screws, rivets, springs, pin stems of brooches, and bracelet and necklace snap tongues, so a coin mark speaks for the silver body of a piece and not every fitting.