999 (fine silver)

How to read it

Silver marks give the pure silver content in parts per thousand. The FTC’s jewelry guides ask for that figure immediately before the word silver, giving 750 silver as their example, so 999 is the figure-first form at its highest. The UK’s Hallmarking Act lists four silver standards and the figures struck for each: 800, 925, 958 and 999, so 999 is the purest silver the Act marks. It is also one of the silver finenesses the International Hallmarking Convention recognises.

Also searched as: .999 silver, 999 silver, fine silver.

999 or 925?

999 is purer than 925 sterling silver, which has 75 parts in every 1,000 of other metals. The two also differ in what the rules call them. The words sterling and solid silver are reserved for silver of at least 925, but neither the FTC’s guides nor the Hallmarking Act gives 999 a word of its own: it is marked with its number.

What “fine silver” means depends on who is writing

There is no defined term. In its 2018 review of the jewelry guides, the FTC itself wrote that commenters said even “fine silver” (i.e., 925 PPT) eventually tarnishes, using the phrase for sterling. A metallurgist whose statement the FTC summarised, Stewart Grice, used it for purer metal, saying fine silver reacts with sulfur and eventually tarnishes, and that alloys with more copper tarnish more quickly and to a greater degree. On a mark, the number settles it.

How close to 999 the silver has to be in the US

For any silver mark other than the words sterling and coin, the Stamping Act lets the actual fineness fall short of the marked figure by no more than four parts per thousand, and by no more than ten when the whole article is assayed as one piece with its solder.

Silver below sterling

Until 2018 the FTC’s guides advised against calling anything under 925 silver at all. The FTC removed that threshold in 2018, saying it was not necessary to prevent deception, so long as the parts-per-thousand figure comes first. In the UK, 800 has been the lowest silver standard since the 1998 amendment regulations replaced 925 with 800 as the minimum fineness, in force from 1 January 1999. Okie’s 1928 survey of European marks notes that the standard of the German Empire had been .800. Under the Hallmarking Convention, 925 and 800 are two of the five standards legal in every member state.

999 in a British hallmark

The figures 999 are struck in the silver shield, beside the sponsor’s mark and the assay office mark. The optional picture mark for 999 silver is the figure of Britannia or a lion passant (a lion rampant at Edinburgh), the same choice the Act gives for Britannia silver at 958.4.

Silver-coloured, silver-plated and EPNS

A silver-coloured finish is not a silver mark. The FTC’s guides say the word silver on a product that only has a surface layer of silver should be qualified to show it is only coated, and the Hallmarking Act allows silver on an unhallmarked article only when it is qualified by the word plated. The Silver Society notes that plated silver carries no silver marks, and that makers often struck imitation hallmarks on it; the commonest is EPNS, which stands for Electro Plated Nickel Silver.

Bars, coins and small pieces

The Hallmarking Act exempts raw material and bullion, including any bar, plate, sheet, foil, rod, wire, strip or tube, and any current or former coin, so a 999 stamp on a bar is not a hallmark. Silver articles under 7.78 grams are exempt too. The FTC’s guides list parts left out of any assay of a silver product, among them screws, rivets, springs, pin stems and bracelet and necklace snap tongues.