925, 800 and the silver marks that mean something

The number is a fineness, not a brand

The number stamped on a silver piece is a millesimal fineness: parts of pure silver per thousand parts of alloy. 925 means 925 parts in a thousand, or 92.5 per cent silver by weight. The remaining 7.5 per cent is usually copper, added because fine silver on its own is too soft to hold a shape, a hinge or a stone setting. That standard has a name – sterling – and most silver jewellery sold in Britain, Ireland and North America is made to it.

Above sterling sits 958, Britannia silver, a higher and softer standard introduced in England in the late seventeenth century and still struck today. Below sterling sit the continental standards. 800 and 830 appear constantly on older German, Austrian, Italian, Dutch and Scandinavian work. Both are genuinely silver, with more copper in them, which makes them harder, slightly warmer in tone and quicker to darken. 900 is coin silver, the fineness of old silver coinage, and turns up on nineteenth-century American flatware.

A piece stamped 800 is not a failed attempt at sterling. It is silver made to a different national standard, and where it was made that standard was the legal one.

The marks you are most likely to find

Two cautions about the word rather than the number. Sterling struck in full is an American convention with no independent testing behind it. And a bare 925 with no other mark can be struck by anyone, anywhere, including onto plated goods, which is why the mark is a starting point and not a result.

A British hallmark and its parts

A piece assayed in the United Kingdom carries three compulsory marks, struck by an assay office after the metal has actually been tested.

1. The sponsor’s mark. Initials in a shaped shield, registered to the firm that submitted the piece.
2. The fineness mark. The number itself – 925, 958, 800 – in a surround whose shape indicates the metal.
3. The assay office mark. A leopard’s head for London, an anchor for Birmingham, a rose for Sheffield and a castle for Edinburgh. Glasgow, Chester, Exeter, Newcastle, York and Dublin appear on older work.

Beside them you may find the lion passant, a lion walking with one forepaw raised, which is the traditional British symbol for sterling. Britannia silver uses a seated figure of Britannia instead. These pictorial marks have been optional since 1999, so their absence on a recent piece means nothing, while their presence on an older one is a strong sign of a properly assayed article.

A date letter – a single letter in a shield, the typeface changing with each cycle – has been voluntary since 1998. Where one survives it dates the assay to a single year. Where there is none, nothing follows.

The words that contain no silver at all

Several familiar terms describe metal with no silver in it whatsoever.

• EPNS – electroplated nickel silver. A thin electroplated layer of silver over a nickel alloy base. The plating is silver; the article is not.
• Silver plate – the same idea by another name, sometimes marked EP or A1.
• Nickel silver, German silver and alpaca, also written alpacca – one alloy of copper, nickel and zinc under three names, called silver for its colour alone.
• Tibetan silver and silver tone – marketing descriptions with no defined composition.

Plated tableware often carries a row of small stamped symbols that look at a glance like a British hallmark. Check for the elements a real one has: initials, a fineness number, a town symbol and usually a lion. A row of shields holding a crown, a flower and a letter but no number is a maker’s device, not an assay.

Telling plate from solid without a laboratory

Four observations, none conclusive alone, which together usually settle it.

Wear at the high points. Plating is thinnest where fingers and cuffs touch: the top of a ring shank, the edge of a bangle, the raised parts of a chased pattern, the rim of a spoon. Look under strong light for a duller, warmer or pinker metal showing through, or a dark grey patch where nickel has been exposed. Solid silver wears thinner in those places without changing colour.

Weight. Silver is dense, and a sterling piece feels heavier in the hand than the same object in plated brass, steel or zinc alloy. This is a comparison rather than a measurement.

Smell. Rub the piece briskly for a few seconds and smell your fingers. Silver is close to odourless. Copper and nickel bases give the sharp coin-like smell of loose change, and a strong smell is a reason to look harder at the edges.

A magnet. Silver is not attracted to a magnet at all, so a pull means ferrous metal: plated steel, a steel clasp spring or a steel brooch pin. A pass proves nothing, since brass, nickel silver and zinc alloys are all non-magnetic too.

Tarnish is evidence, not damage

Silver reacts with sulphur compounds in the air to form silver sulphide, a film that goes straw yellow, then brown, then black. It is a surface effect and it removes nothing from the metal. Pieces stored with wool, rubber bands or newspaper darken faster, and so does anything worn against skin in a warm room.

Two things follow. A silver-coloured piece that has never tarnished after years in a box deserves a second look, although rhodium-plated silver, common on modern chain and settings, genuinely does not tarnish and neither does stainless steel. And lower standards behave differently: the extra copper in 800 and 830 darkens faster and can leave a greenish trace on skin.

Black in the recesses of engraved or chased work is often deliberate oxidation, put there to give the pattern depth. A dip that strips every trace of tarnish takes that with it, and on an antique piece there is no way back.

A silver-coloured piece with no mark

Unmarked does not mean base metal. British hallmarking is compulsory only above 7.78 grams of silver, so light earrings, thin chains, small charms and slender stacking rings are sold with no mark entirely lawfully. Many countries never operated an assay system, older pieces predate the relevant law, a resized shank may have lost the marked section, and polishing flattens a shallow punch. There is more in what a missing hallmark does and does not mean.

What settles fineness is a test on the metal itself. An acid and touchstone test cuts through any coating at the cost of a small scratch in an inconspicuous place. X-ray fluorescence at a jeweller reads the alloy without marking the piece, though it sees only the top few microns and can be misled by heavy plating.

From photographs, Carat transcribes what is actually struck – 925 stays 925 – then interprets it and flags plating signs such as edge wear and colour change where the images show them. Treat it as a way of sorting a drawer into pieces worth testing, alongside the checks above rather than instead of them. Reading gold hallmarks covers the same ground for the yellow metals.