By Rocco Clayfield, Founder & Director, GoldPaid Ltd · Published 6 August 2026
What the five numbers actually are
Every one of these is a millesimal fineness figure, meaning parts of pure gold per thousand parts of the finished alloy. 750 is 750 parts gold and 250 parts of something else. The same arithmetic runs through all of them. What changes from mark to mark is which country wrote the rule, and how that country decided to round the carat fraction.
| Mark | Carat | Pure gold by weight | Usually from | A legal British standard? |
|---|---|---|---|---|
| 333 | 8ct | 33.3% | Germany, Austria, Scandinavia | No |
| 375 | 9ct | 37.5% | United Kingdom | Yes |
| 417 | 10ct | 41.7% | United States, Canada | No |
| 583 | 14ct (Soviet) | 58.3% | USSR and pre-1990s Russia | No |
| 585 | 14ct | 58.5% | UK, Germany, USA, Turkey | Yes |
| 875 | 21ct | 87.5% | Gulf states, Egypt, Jordan | No |
| 916 | 22ct | 91.6% | UK, India, Middle East | Yes |
375 and 916 are in the table as reference points rather than because anyone puzzles over them. If you want either of those on its own, what 375 means on gold and what 916 means on gold take them apart in full, and what 585 means on gold covers modern 14 carat.
Why four of these five cannot be hallmarked in Britain
Schedule 2 of the Hallmarking Act 1973 sets out the standards of fineness a UK assay office is permitted to mark gold to. The list is 375, 585, 750, 916.6, 990 and 999. There is no entry for 333, 417, 583 or 875, so no British office in London, Birmingham, Sheffield or Edinburgh can strike those numbers, whatever the metal turns out to be on testing.
The international route does not add them either. The Convention on the Control and Marking of Articles of Precious Metals, whose Common Control Mark is recognised in the UK, covers gold at 999, 916, 750, 585 and 375. It stops at the same floor.
There is one practical consequence worth understanding. A foreign fineness number will not have a UK assay office symbol beside it, so what you are reading is a manufacturer's declaration rather than an independent certification. That is a real difference, and it is the gap that testing closes. Our complete guide to UK gold hallmarks sets out what a full British mark looks like by comparison.
417: American 10 carat
417 is the United States 10 carat mark. Ten parts of gold in twenty-four is 41.666 per cent, and the stamp rounds it up to 417. The US National Stamping Act allows a tolerance of three parts per thousand on an article with no solder, and seven parts per thousand where solder is present, which is why an XRF reading of 414 or 415 on a 417-stamped chain is normal rather than alarming.
Ten carat is a little under 60 per cent base metal, mostly copper with silver and zinc. It is hard, it takes and holds a deep engraving, and over decades it can pick up a faintly pink cast or a dull surface film. That is the copper doing what copper does, not a sign that the piece is fake.
In a British drawer, 417 almost always means American family or an American posting. The single most common item is the US class ring, the heavy engraved school or college ring that American teenagers have bought for generations and that is overwhelmingly made in 10 carat. After that come imported rope and figaro chains, Black Hills gold rings with their applied leaves, and charm bracelets brought back from trips.
333: eight carat, and the one word you cannot use here
333 is 8 carat, 33.3 per cent gold and two-thirds something else. It has long been the customary floor for jewellery sold as gold in Germany and Austria, and it appears in Dutch and Scandinavian retail as well. To a German shopper it is an ordinary, unremarkable everyday standard.
In Britain the law reads differently. 333 sits below 375, the lowest fineness the Hallmarking Act 1973 recognises for gold, so no UK assay office can hallmark it. The Act also makes it an offence for a person acting in the course of a trade or business to describe an un-hallmarked article as being wholly or partly made of gold. In practice that means a UK trader should not simply call an 8 carat piece "gold" without qualifying it. You can own it, wear it, inherit it and sell it. It is a labelling rule, not a judgement on the metal, and it does not stop the metal being bought and refined.
Because it is two-thirds base metal, 8 carat is noticeably paler and cooler than 9 carat, and some 333 alloys darken or develop a greenish tinge against skin over the years. Neither tells you anything about whether it is genuine. XRF reads the actual composition in seconds, which is the point of testing rather than trusting a stamp. XRF testing explained covers how that works.
Not sure how any of this applies to your own items? Send a photo on WhatsApp and ask. We answer honestly, there is no obligation, and nothing is posted until you decide. Or call 07763 741067, 8am to 9pm, 7 days a week.
583 and 585: two thousandths apart
583 was the Soviet 14 carat standard, one of five gold standards in the Soviet system alongside 375, 500, 750 and 958. Russian production moved to 585 in the 1990s to line up with international practice. The year is commonly given as 1994, though we have not found a primary source we would stake a claim on, so treat the date as approximate. What is not in doubt is what the number tells you: a 583 stamp means the piece is Soviet-era.
The gap between the two standards is two parts per thousand. On a 10 gram wedding band that is 0.02 grams of pure gold, which at the dated fine-gold figure further down this page is around two pence. Anyone presenting 583 as materially inferior to 585 has not done the arithmetic.
Soviet pieces often carry a state assay mark showing a hammer and sickle inside a five-pointed star, raised in relief between 1958 and 1965 and recessed from then on, usually with one or two Cyrillic letters identifying the assay office. Those marks are worth photographing before anything is sold, because a piece with an intact Soviet mark set is sometimes of more interest to a collector than to a refiner.
875: 21 carat, or silver
875 is 21 carat, 87.5 per cent gold, and it is the working standard of Gulf gold jewellery. Saudi Arabia, the United Arab Emirates, Kuwait, Qatar, Jordan and Egypt all trade heavily in 21 carat, because it holds the deep yellow colour that market expects while staying just workable enough for chains, bangles and the heavy link sets sold by weight in the souks. It reaches Britain through Gulf work postings, family in the region, and holiday purchases in Dubai.
The two separate in seconds without any equipment. 21 carat gold is unmistakably deep yellow and startlingly heavy for its size, because gold is roughly one and a half times as dense as silver. A silver piece of the same dimensions feels ordinary in the hand and is white or grey, going grey-black where it has tarnished. If you are unsure, photograph the mark and the piece together and send it on WhatsApp before posting anything.
What each mark is worth as metal
Nothing about a foreign mark changes the valuation method. The metal content of any piece is its weight multiplied by its fineness, and the market decides the rest. Using the dated fine-gold figure of £101.70 per gram from 6 August 2026 (BullionVault GBP spot, 6 August 2026), the metal inside one gram of each alloy works out as follows.
| Mark | Carat | Fineness | Spot metal content per gram of alloy, 6 Aug 2026 |
|---|---|---|---|
| 333 | 8ct | 0.333 | £33.87 |
| 375 | 9ct | 0.375 | £38.14 |
| 417 | 10ct | 0.417 | £42.41 |
| 583 | 14ct (Soviet) | 0.583 | £59.29 |
| 585 | 14ct | 0.585 | £59.49 |
| 875 | 21ct | 0.875 | £88.99 |
| 916 | 22ct | 0.916 | £93.16 |
That column is the market value of the gold inside one gram of alloy on one dated day. It is not what any buyer pays, and no buyer in the country pays it. Refining, assay, handling, the working-capital gap and margin sit between spot and every consumer offer, at every reputable firm. The components are broken down in spot price versus scrap price, and if you are reading this on a different day, use that day's rate from the gold price today page or the August 2026 price update.
The number that surprises people is what happens when weight is taken into account. A 30 gram German 333 chain holds 9.99 grams of pure gold. A 6 gram Gulf 875 ring holds 5.25 grams. The chain has almost twice the recoverable gold of the ring despite carrying the lowest mark in the table. Mass matters at least as much as fineness, which is why guessing from the stamp alone is a poor way to work out what a mixed drawer is worth.
Final offers depend on inspection, item weight, purity, hallmarks, stones, non-gold components, condition and the live precious-metal market.
When posting is not the right answer
We buy metal, and we pay on measured metal content. For some pieces carrying these marks, that is not the best route, and it is worth saying so plainly before you pack anything.
- Recent, unworn 21ct Gulf jewellery. In the Gulf, 21 carat is bought and sold back close to metal value with a modest making charge on top, so a set bought in Dubai last year and never worn may do better sold back into that market through family, or to a UK dealer who specialises in 21 carat as jewellery, than melted for its content here.
- American class rings. There is a small but real collectors' market for US class rings with a named school, year and initials. A quick search on the school name is worth five minutes before treating one as scrap.
- Intact Soviet pieces with a full mark set. A 583 ring or an 875 silver case with a clean hammer-and-sickle assay mark and a maker's mark can hold collector interest above its melt figure. Photograph the marks and check before deciding.
- A single very light 333 item. A 1.5 gram 8 carat charm holds half a gram of gold. On its own that is not worth the trip to the Post Office. Put it in with other items, or leave it where it is.
- Anything marked 417 GF, 333 GP, 14K GE or similar. Those suffixes mean gold filled, gold plated or gold electroplated, not solid gold. Gold filled versus gold plated versus vermeil explains what each is actually worth.
Everything else in this family posts the same way as British-marked gold. Send a photo first, get an indicative figure, and decide afterwards. The full method is on the sell gold by post page, and how we value gold sets out the calculation itself.
How a foreign-marked parcel is handled
- Photograph the marks and the piece and send them on WhatsApp to 07763 741067. We will tell you honestly what the mark appears to be, including when it looks like silver rather than gold, and what we can and cannot tell from a photograph.
- If you want to go ahead, we send a prepaid Royal Mail Special Delivery label, usually within 30 minutes during working hours. Royal Mail cover may be available up to £2,500 depending on the postal method and cover level used.
- Every item is XRF-assayed on arrival and weighed on calibrated scales. The foreign stamp is the starting point; the tested composition is what the offer is built from.
- You get a written, itemised offer showing the purity found, the weight and the rate used. Nothing is firm before inspection.
- Accept and payment goes out by Faster Payments within one working hour of acceptance. Decline and the whole parcel comes back to you free of charge by tracked post.
Mismatches between stamp and metal do happen with imported pieces, in both directions. A 417 chain repaired with a lower-carat solder tests slightly under. A 333 piece from a maker working above the minimum tests slightly over. Either way the offer follows the measured metal rather than the stamp, which is the only version of this that is fair to both sides.
Sources
- Hallmarking Act 1973, Schedule 2, standards of fineness for gold, silver, platinum and palladium: legislation.gov.uk
- Assay Office London, hallmarking guidance notes, legal standards and exemption weights: assayofficelondon.co.uk
- Convention on the Control and Marking of Articles of Precious Metals, finenesses covered by the Common Control Mark: Dublin Assay Office and hallmarkingconvention.org
- US National Stamping Act tolerances, as applied by the FTC Jewelry Guides at 16 CFR Part 23: ecfr.gov
- Fine gold price of £101.70 per gram and £3,163.19 per troy ounce, BullionVault GBP spot, 6 August 2026, as recorded in our August 2026 price update.
Where a fact is contested we have said so rather than smoothing it over. The date Russia moved from 583 to 585 is the clearest example: it is widely reported as 1994, and we have not found a primary source for it, so it is given here as approximate.
Common questions
Is 417 real gold?
Yes. 417 is the American mark for 10 carat, 41.7 per cent pure gold by weight. It is not a legal British hallmarking standard, so a UK assay office cannot strike it, but the metal is genuine gold and is bought and refined in the ordinary way.
Can 333 gold be hallmarked in the UK?
No. At 33.3 per cent it falls below 375, the lowest gold fineness listed in Schedule 2 of the Hallmarking Act 1973, so there is no UK standard for it to be marked against. The Act also makes it an offence to describe an un-hallmarked article as gold in the course of a trade or business, so a UK trader should qualify rather than simply call it gold. You can still own it, wear it and sell it.
Is 583 worth less than 585?
By two parts of gold in a thousand, which on a 10 gram ring is 0.02 grams. At the 6 August 2026 fine-gold figure of £101.70 per gram that is about two pence. Any buyer treating 583 as a materially inferior standard is not doing the arithmetic.
Does an 875 stamp always mean gold?
No, and this is the mark that catches people out. 875 was a Soviet silver standard as well as the Gulf 21 carat gold standard. A dark, light, white-metal item stamped 875 with Cyrillic letters beside it is far more likely to be Soviet silver. Gold at 87.5 per cent is deep yellow and heavy for its size.
Is 21 carat better than 18 carat?
It holds more gold per gram, 87.5 per cent against 75 per cent, so the metal content is higher. It is also softer and marks more easily in daily wear. Which is better depends on whether you are wearing it or weighing it.
Why has my German 333 chain gone dull or coppery?
Because two thirds of the alloy is base metal, mostly copper, silver and zinc. Those metals oxidise slowly at the surface. The gold content itself does not tarnish, and polishing usually restores the colour.
Do you buy jewellery with foreign marks?
Yes. Foreign-marked pieces are handled exactly like British ones: XRF-assayed on arrival, weighed on calibrated scales, and paid on the measured metal content rather than on the stamp. The mark is a starting point, not the valuation.
Will 875 pay more per gram than 916?
No. 916 holds 91.6 per cent gold against 87.5 per cent, so per gram of alloy it contains more metal. Total weight still matters more than the mark on any single piece, because mass multiplied by fineness is what decides the recoverable gold.
What if the mark on my piece is worn away completely?
It is tested rather than read. XRF spectrometry measures the actual composition without acid or scratching, which is why a missing or unreadable stamp does not stop a piece being valued properly.
Is a foreign stamp a sign of a fake?
Not in itself. It means the piece was marked to another country's rules. What it does mean is that no independent UK assay office has certified it, so the number is the maker's claim. Testing is what settles the difference, and counterfeit stamps on base metal do exist in every marking system.