What Is a Hallmark? How to Read the Tiny Stamps in a Ring
Almost every ring has something written inside it, and almost nobody knows what it says. A ring made in Birmingham carries a row of five marks struck by a government-linked laboratory. A ring made in Coquitlam carries two marks applied by the person who made it. Both can be honest. They mean different things, and that difference is worth knowing before you buy or sell anything.
A hallmark and a quality stamp are two separate things
People use the word hallmark for any stamp inside a ring. In the trade it means one thing: a mark struck by an independent assay office after that office has tested the metal. The office is not the seller and makes nothing on the sale. It takes a scraping, tests it, and strikes its mark only if the metal passes.
A maker's quality stamp is a different act. The manufacturer tests its own alloy, or trusts its supplier, then stamps 14K on the band. That number is usually correct, because good makers control their metal carefully. The claim rests on the maker's word.
How the British system works
Britain runs compulsory independent assay. Under the Hallmarking Act 1973, a precious metal article cannot be sold as gold, silver, platinum or palladium unless a UK assay office has hallmarked it. Four offices operate: London, Birmingham, Sheffield and Edinburgh. The Assay Office London lists three compulsory marks:
- The sponsor's mark. Initials in a shaped shield, naming whoever submitted the article.
- The fineness mark. Metal content in parts per thousand: 375, 585, 750, 950.
- The assay office mark. The town symbol of the testing office. London strikes a leopard's head.
Two more are optional: a pictorial symbol for the metal, such as a crown for gold, and a date letter that changes every 1 January. The date letter is why a British piece can often be dated to a single year, which helps when you inherit something.
Small articles are exempt. Schedule 1 sets the thresholds at 1 gram for gold, 7.78 grams for silver, 0.5 gram for platinum and 1 gram for palladium.
Canada took a different route
There is no compulsory independent assay office here, and the Competition Bureau states that applying a quality mark to precious metal articles is not mandatory at all.
Canada replaces the testing step with a naming step. Section 4(3) of the Precious Metals Marking Act requires that where a quality mark is applied, a mark that is a registered trademark under the Trademarks Act, or one with an application acceptable to the Minister already filed, shall also be applied to the article.
Section 5 of the Precious Metals Marking Regulations adds a detail you can inspect: where a quality mark is stamped, branded, engraved or imprinted, the trademark shall be applied by the same method. The two marks sit together, made the same way.
So the Canadian rule is this: a karat number belongs on a ring only when a registered name sits beside it. A bare number means somebody skipped a legal requirement, and we treat that as a reason to test before quoting.
Section 4(4) writes in one exception: the trademark requirement drops away where an article is hallmarked under the laws of the United Kingdom, or carries a foreign government mark that truly indicates quality. Canadian law accepts a British hallmark on its own.
What the numbers actually mean
Two notations describe the same metal. Karat counts parts out of 24. Millesimal fineness counts parts out of 1,000.
| Mark you will see | Metal | Parts per 1,000 | Karat equivalent | Notes |
|---|---|---|---|---|
| 375 | Gold | 375 | 9K | Canada's legal minimum for a gold mark is 9 karats |
| 417 | Gold | 417 | 10K | Common in Canada and the United States |
| 585 or .583 or 14K | Gold | 585 | 14K | Our most requested metal for daily wear |
| 750 or 18K | Gold | 750 | 18K | Richer colour, softer surface |
| 925 or STERLING | Silver | 925 | Not applicable | Regulations set a 925 minimum for sterling |
| PT950 or PLAT | Platinum | 950 | Not applicable | Regulations require 95 per cent minimum |
Canada's regulations set the gold minimum at 9 karats and allow quality in karats or decimals, using karat, carat, Kt., Ct., K or C. Silver's minimum is 925 parts per 1,000, and platinum and palladium each require 95 per cent metallic content. For the practical side of choosing, we compared 14K and 18K for everyday wear.
The .583 question
Older Canadian and American pieces often read .583 where a modern piece reads 585. 14 divided by 24 is 0.58333, so 14K gold is 583.3 parts per 1,000, and a maker rounding down truthfully arrived at 583. The international convention rounds up to 585.
Canada's regulations fix no list of approved gold numbers. Section 6 says the decimal number used shall be in the same proportion to the number 1 as the quality of the gold is to pure gold. A truthful 583 and a truthful 585 both satisfy that.
The gap is 2 parts in 1,000, which is 0.008 grams on a 4 gram ring. Anyone offering you less per gram for a .583 stamp is using the mark as an excuse.
Tolerances matter more than the rounding. The regulations allow gold without solder to fall short by 3 parts per 1,000, and gold containing solder by 7 parts per 1,000, rising to 15 parts for white gold of 18K and above.
Reading a worn or missing stamp
Stamps wear away. The inside of a band rubs against skin for decades and the metal flattens. What works on our bench:
- Clean first. Polish compound and skin oil pack into the depressions and fill them level.
- Light from the side. Angle it across the band, so shadow falls into whatever depth remains.
- Magnify. A 10x loupe resolves most marks; our bench scope handles the rest.
- Photograph and enlarge. A phone macro shot blown up on screen shows what an eye cannot hold steady enough to see.
- Read the shield. When characters are gone, the surrounding outline can still identify the system.
Resizing is the other reason marks vanish. Sizing cuts the band at the bottom, often the exact spot the stamp sits. Sizing down removes it; sizing up replaces it with new unmarked metal. We check where the marks are before we cut.
An unmarked piece still needs testing, not a verdict
No stamp does not mean no gold. Marking is voluntary in Canada, British small articles are exempt by weight, handmade pieces from unregistered makers are unmarked as a matter of course, and resized rings lose stamps every day.
The honest answer to an unmarked ring is a test. An acid test on a scraping reads well for a few dollars of consumable. X-ray fluorescence reads the alloy without marking the piece, and it is what we reach for on anything we might buy.
For your rights when a mark turns out to be wrong, see our guide to hallmarks, karat stamps and your rights.
Pieces we made and marked ourselves
Everything below carries its quality mark and our registered trademark, applied the same way, as the regulations require.
Key Takeaways
- A true hallmark is struck by an independent assay office that tested the metal. A karat stamp is the maker's own declaration, and Canada uses the second type almost exclusively.
- A full British hallmark carries three compulsory marks: sponsor's initials, fineness number and assay office town mark, plus an optional date letter that pins the year.
- Canadian law requires a registered trademark beside any quality mark, applied by the same method, so a bare number with no maker's name is a warning sign.
- 585 and .583 both describe 14K gold, because 14 divided by 24 is 0.58333. That 2 parts per 1,000 gap is 0.008 grams on a 4 gram ring and should not change your price.
- An unmarked piece can be solid gold. Resizing removes stamps routinely and small British articles are exempt by weight, so test the metal.
Frequently Asked Questions
What is the difference between a hallmark and a karat stamp?
A true hallmark is struck by an independent assay office after that office has tested the metal itself. The office has no stake in the sale, so the number is backed by a laboratory that answers to a regulator. A karat stamp is applied by the manufacturer and records what the maker says the metal is. Both can be accurate. One has been checked by an outside party and the other has not. Britain's Hallmarking Act 1973 requires that test for gold articles above 1 gram, and four offices carry it out. Canada has no compulsory assay office, so almost every stamp on a ring bought here is a maker's declaration rather than a laboratory result. Neither system makes a ring good or bad on its own. Knowing which one you are reading tells you how much the number is worth, and whether anybody independent ever checked it.
Does Canada have an assay office that tests jewellery?
Canada has no compulsory independent assay office of the British type. Nobody is required to send a ring away for testing before it can be sold here. The Competition Bureau confirms that applying a quality mark to a gold, silver, platinum or palladium article is not mandatory in the first place. Canada uses a different mechanism. Under section 4(3) of the Precious Metals Marking Act, once a quality mark is applied, a registered trademark must be applied as well. The law makes the maker sign the claim. If the metal is wrong, a registered name is attached to it and that name can be pursued. Canada gives you accountability after the fact where Britain gives you testing before the sale. Both put a real party behind the number, which is why we tell people to look for the maker's mark beside the karat stamp on anything bought here.
Why must a Canadian quality mark be accompanied by a trademark?
Because the trademark is what makes the number enforceable. A bare "14K" stamp with no name beside it identifies nobody, so there is no one to answer for it if the metal tests at 10K. Section 4(3) of the Precious Metals Marking Act requires that where a quality mark is applied, a registered trademark under the Trademarks Act, or one with an application acceptable to the Minister already filed, must also be applied. Section 5 of the regulations adds that if the quality mark was stamped, branded, engraved or imprinted, the trademark has to be applied by the same method. The two marks sit together, made the same way, which makes them easy to check with a loupe. A karat number standing alone means somebody skipped a step, and that is the moment to ask questions before you pay.
What do 585, 750 and 925 mean?
They are millesimal fineness numbers, which means parts of pure metal in every thousand parts of alloy. 585 is 585 parts gold per thousand, the same metal sold as 14K in Canada. 750 is 750 parts per thousand, which is 18K. 925 is 925 parts silver per thousand, the sterling silver standard, and Canada's regulations set that same 925 minimum for anything marked sterling. PT950 means 950 parts platinum per thousand. The system is useful because it works in any language and needs no conversion. A ring marked 750 means the same thing in Coquitlam, London and Milan. Karat marks and fineness numbers describe identical metal in two notations, so 18K and 750 on two different rings tell you the same fact.
Why do some older Canadian pieces say .583 instead of 585?
The arithmetic explains it. 14 divided by 24 is 0.58333, so 14K gold is 583.3 parts per thousand, and a maker who rounded that down honestly reached 583. The modern international convention rounds up to 585, which describes alloy mixed with a small margin above the minimum. Canada's regulations do not name a fixed list of numbers for gold. Section 6 says the decimal number used shall be in the same proportion to the number 1 as the quality of the gold in the article is to pure gold, which permits either figure when it is truthful. The gap is 2 parts in 1,000, which is 0.008 grams on a 4 gram ring. We pay the same per-gram rate for both.
Is an unmarked ring fake?
No, and treating it that way costs people money. Marking is voluntary in Canada, so a piece can be solid 18K and carry no stamp at all and break no rule. Britain exempts small articles from compulsory hallmarking: gold under 1 gram, silver under 7.78 grams, platinum under 0.5 gram and palladium under 1 gram, per Schedule 1 of the Hallmarking Act 1973. Handmade and older pieces are often unmarked because the maker never registered a trademark. Resizing removes stamps too, since the stamped part of the band is usually what gets cut out. When the mark is missing, test the metal rather than assume. We do that on our bench with an acid test or an X-ray fluorescence reading, and we will tell you what the piece is either way.
How can I read a stamp that is worn down?
Start with light and magnification rather than guesswork. A 10x loupe plus a strong light angled across the band, instead of straight down, throws shadow into the remaining depressions and lifts characters that look invisible under flat light. Clean the band first, because old polish and skin oil pack into the stamp and fill it level. Photograph the mark with a phone macro lens and enlarge it on screen, which often resolves what an eye cannot. When the characters are gone, the shape of the surrounding shield still identifies the system, because British marks sit in distinctive outlines. If part of a number survives, the digit count narrows it: three digits is fineness, two digits with a K is karat. Bring the piece in and we will put it under the bench scope while you wait. If the mark is beyond reading, we test the metal instead and tell you what the piece actually is.
Does resizing a ring remove the hallmark?
It often does, and that is a normal consequence rather than damage. Makers stamp the inside of the band, and sizing work cuts the band at the bottom, which is frequently the exact spot the stamp occupies. Sizing down removes a section outright. Sizing up adds new metal there, and the added piece carries no mark. A careful goldsmith checks where the stamp sits before cutting and works around it when the size change allows. In Britain, altering a hallmarked article can send the piece back to an assay office for re-hallmarking. Canada has no such step. We record the original marks before we cut, so the information survives even when the stamp does not. Our guide to ring resizing covers what else changes.
Which country's mark am I looking at?
Work from the number of separate marks. A run of four or five small stamps in a line, each in its own shaped shield, is a British hallmark: a sponsor's mark of initials, a millesimal number, a town mark and often a date letter. One number plus one small logo is the Canadian and American pattern, a maker's quality mark with its trademark. A single number with nothing beside it was marked outside any accountability system, and we treat that as a reason to test. European pieces often carry a fineness number with a small national symbol. Britain also recognises marks from other countries through the international convention on hallmarks, so a Common Control Mark showing a balance scale may appear in place of a town mark. Bring the piece in and we will read it with you rather than have you guess from a phone photo.
Sources
- Justice Laws Canada: Precious Metals Marking Act (R.S.C., 1985, c. P-19), sections 4(3) and 4(4)
- Justice Laws Canada: Precious Metals Marking Regulations (C.R.C., c. 1303), sections 5, 6 and 13
- Competition Bureau Canada: Precious metals marking
- Competition Bureau Canada: Guide to the Precious Metals Marking Act and Regulations
- UK Legislation: Hallmarking Act 1973
- UK Legislation: Hallmarking Act 1973, Schedule 1 exemption weights
- Assay Office London: What is a Hallmark
Data sourced September 2026. Legal citations were read against the current consolidated text on the day of writing. Bench methods are our own practice.
Visit Vanhess
We are a family-run studio at 2929 Barnet Highway in Coquitlam, and we designed and made most of what sits in our cases. Bring in any mark you cannot read and we will put it under the bench scope while you wait, whether you bought the piece from us or inherited it from a grandmother in Sheffield. If the mark is gone we will test the metal and tell you what it is. Call us at +1 (604) 653-6449.
