What the Rolex St. Bernard hallmark means
The dog inside a gold or platinum case, and the guarantee behind it.
The little dog's head stamped inside a gold or platinum Rolex is the official Swiss hallmark. It means that a government assay office tested the metal and confirmed it to be at least as pure as the number stamped beside it on the case.
That is the entire job of the Rolex St. Bernard hallmark. It isn't a Rolex logo, a model code, or a maker's mark.
Rolex doesn't even put it there, a Swiss assay office does, after testing the case.
Since 1995 the St Bernard has been Switzerland's single official hallmark for every precious metal. Gold, platinum, silver and palladium all get the same St. Bernard. The number next to it is what changes, 750 for 18k gold and 950 for platinum.
On a Rolex you'll find it on solid gold and platinum models, such as the gold Day-Date, Daytona, Sky-Dweller and GMT-Master II, and the platinum Day-Date and Daytona. Steel models never carry it, because steel isn't a precious metal and there's nothing to assay.
Quick facts
Why it matters to a buyer
The hallmark does three useful things. It confirms the case metal, it helps date the caseback, and it hints at where the watch was first sold.
What it can't do is prove the watch is a genuine Rolex, as some fakes attempt to replicate the dog. That part trips people up more than anything else, so it gets its own section below.
The short version
Here's what the dog stamp on a gold Rolex tells you, and what it doesn't.
- The St. Bernard head is Switzerland's official hallmark for all precious metals, in use since 1995 and still current as of October 2026.
- It guarantees the metal is at least as fine as the number beside it, so 750 means at least 75 percent gold, or 18k.
- A small letter on the dog identifies the assay office that struck it, such as G for Geneva.
- Before 1995, gold Swiss cases carried Helvetia's head for 18k or a squirrel for 14k, which makes the marks a quick way to date a caseback.
- Swiss law only requires the hallmark on precious metal watch cases sold in Switzerland, so plenty of genuine gold Rolex watches don't have one.
- The catch: it certifies metal, not authenticity. Hallmarks can be faked, and the dog alone never proves a Rolex is real.
How to read Rolex caseback hallmarks
The dog rarely appears alone, this is what sits next to it.
A fully hallmarked Swiss gold case can carry up to four official marks, and each one answers a different question.
| Mark | What it looks like | What it tells you |
|---|---|---|
| Official hallmark | Head of a St. Bernard with a small letter | A Swiss assay office tested the metal |
| Fineness mark | A number such as 750 or 950 | Purity in parts per thousand |
| Common Control Mark | Fineness number inside a balance scale | Tested under the international Hallmarking Convention |
| Responsibility mark | A registered maker's symbol | Who is legally responsible for the metal content |
Rolex also engraves its own markings inside the caseback, such as its name and the metal. Those are brand marks and carry no official guarantee.
The letter on the dog
Look at the hallmark under a loupe and you'll find a tiny letter on the dog's head. It tells you which Swiss assay office struck the mark.
| Assay office | Letter |
|---|---|
| Geneva | G |
| La Chaux-de-Fonds | C |
| Biel/Bienne | B |
| Le Noirmont | J |
| Chiasso | T |
| Zurich | Z |
Office list per the Swiss Federal Office for Customs and Border Security, verified October 2026. Older pieces can carry letters from offices that have since closed.
What the 750 stamp means on a Rolex
The fineness number is parts per thousand. 750 is 75 percent gold, which is 18k. 950 is 95 percent platinum. 585 is 14k gold, which turns up on some older Swiss watches but never on a modern Rolex.
Rolex casts its own gold alloys in-house, and every one of them, yellow, white and Everose, is 18k. On a modern gold Rolex you should only ever see 750. On a platinum one, 950.
Where to look
Inside the caseback is the classic spot. Swiss makers also strike hallmarks on the case itself, often on the underside of the lugs where the bracelet hides them.
Rolex casebacks screw down against a gasket. Opening one takes a proper case wrench, and an Oyster should be pressure tested once it's closed again. This isn't a kitchen-table job. Ask the seller to show you, or pay a watchmaker.
Helvetia, the squirrel and the 1995 switch
How the old Swiss hallmarks help date a gold Rolex.
Helvetia's head inside a gold Rolex caseback means it was hallmarked before 1995. A St. Bernard means 1995 or later.
Swiss federal hallmarks for gold and silver watch cases date back to the early 1880s, with platinum added in 1914. Until 1995, each metal and purity standard had its own symbol.
| Pre-1995 symbol | What it marked |
|---|---|
| Head of Helvetia | 18k gold, 750 |
| Squirrel | 14k gold, 585 |
| Lynx | Imported cases of at least 14k gold |
| Chamois, an alpine mountain goat | Platinum, 950 |
Silver had its own separate set of symbols. All of them were replaced by the single St. Bernard hallmark in 1995.
Helvetia is the female figure who personifies Switzerland, the same one you'll see on Swiss coins. On a 1960s or 1970s gold Day-Date, Datejust or Cellini, she's the mark you'd expect to find.
Using the marks to check a caseback
This is where the hallmark earns its keep. Match the mark to the era of the serial number.
A watch with a 1980s serial and a St. Bernard inside the back almost certainly has a replacement caseback, often fitted during a Rolex service. That isn't automatically bad. It should be disclosed, though, and collectors of vintage references care about it.
The reverse is a bigger problem. A Helvetia head on the back of a 2000s watch means the caseback came from an older watch, and you want to know why.
Watches made right around 1995 can go either way, since the stamp reflects when the case was assayed. Give the transition years some slack.
Got a vintage gold Rolex with Helvetia marks?
Send us photos and the reference, and we'll come back with a real offer, paid same day if you take it.
Why some gold Rolex watches have no St. Bernard hallmark
A missing dog is usually a paperwork question.
Swiss law requires the St. Bernard hallmark on precious metal watch cases sold in Switzerland. A gold Rolex first sold in the US, Asia or the Middle East doesn't legally need one, so many genuine pieces don't have it.
According to the Swiss Federal Office for Customs and Border Security, which runs precious metals control, official hallmarking is compulsory for gold, silver, platinum and palladium watch cases sold in Switzerland, whether they were made there or imported. For other precious metal goods it's optional. A gold watch built in Geneva for export can skip the assay office.
Switzerland is also part of the international Hallmarking Convention and has recognition agreements with several neighbors. That's why watches headed for Europe often carry the balance-scale Common Control Mark next to the dog.
Other reasons you won't find it
Steel Oyster models have nothing to hallmark. Two-tone Rolesor watches have a gold bezel, crown and center links, but the case and caseback are steel, so the back stays blank.
The marks may also be under the lugs, hidden by the bracelet. And decades of heavy polishing can soften or erase shallow stamps, especially on lugs.
Don't overreact to a missing mark
We'd rather see a correct 750, correct Rolex markings and a movement that matches the reference than a perfect dog on a watch with problems elsewhere. A missing hallmark on an export watch is normal. A badly struck one is not.
Does the St. Bernard hallmark prove a Rolex is real?
What the stamp guarantees, and where it stops.
No. The St. Bernard proves the case metal passed a Swiss assay. It says nothing about whether the dial, the movement or the watch as a whole is genuine Rolex.
Counterfeit hallmarks exist, mostly at the low end of the secondary market. Stamping a dog's head into a plated case costs next to nothing compared with what a fake gold Day-Date sells for.
The opposite problem is sneakier. A genuine gold case can be fitted with a swapped movement or a redone dial, and its hallmark would be completely real.
What we look at on the hallmarks
When a gold Rolex comes across our counter, the hallmarks go under a loupe early because they're quick to check. A real Swiss strike is crisp and evenly deep, with a clean outline on the dog and a readable office letter. Soft, shallow or lopsided stamps get a second look.
We also check that the marks agree with each other and with the metal. The fineness number, the balance-scale mark and the case itself should all tell the same story. A 750 on a case that feels light for its size, or wear that shows a different color underneath, ends the conversation.
What actually authenticates a Rolex
The hallmark is one checkpoint. The serial and reference numbers, the movement, the dial printing, the bracelet and clasp codes, and the papers do the heavy lifting. If you're buying a gold Rolex privately, pay a watchmaker to open it.
Value is a separate question. A hallmark doesn't add a premium on its own. For where gold references trade right now, see our Rolex watch market report.
Want a second set of eyes on a gold Rolex?
Book a time at our showroom in the California Jewelry Mart and we'll go through it with you.
Why Switzerland chose a St. Bernard
The short story behind the dog.
We couldn't find an official explanation from the Swiss authorities, but the choice is easy to read. The St. Bernard is Switzerland's national dog.
The breed takes its name from the Great St Bernard Hospice, the alpine refuge on the pass between Switzerland and Italy, where monks kept dogs to help travelers caught in the snow. The most famous of them, Barry, is credited with saving more than 40 people in the early 1800s.
It was the first breed entered in the Swiss Stud Book, in 1884. Swiss hallmarks have always used national imagery instead of plain numbers, Helvetia for gold and alpine animals for the rest. When everything was folded into one mark in 1995, a dog known worldwide for reliability was a sensible pick for a stamp that vouches for metal.
Rolex St. Bernard hallmark FAQ
What is the dog stamp on a Rolex caseback?
It is the head of a St. Bernard, Switzerland's official hallmark for precious metals. It means a Swiss government assay office tested the gold or platinum and confirmed it is at least as pure as the fineness number stamped beside it, such as 750 for 18k gold.
When did Switzerland start using the St. Bernard hallmark?
In 1995. It replaced the older set of symbols, including Helvetia's head for 18k gold and the squirrel for 14k gold, and became a single hallmark for every precious metal and every fineness standard. It is still in use as of October 2026.
Does the St. Bernard hallmark mean my Rolex is real?
No. It only certifies the metal content of the case. A genuine hallmark can sit on a case with a swapped movement or a fake dial, and hallmarks themselves can be counterfeited. Authenticity comes from checking the serial and reference numbers, movement, dial, bracelet and papers.
Why doesn't my gold Rolex have a St. Bernard hallmark?
Swiss law only requires official hallmarking on precious metal watch cases sold in Switzerland. A gold Rolex first sold in another country often carries just the 750 fineness mark and Rolex's own markings. The marks may also be under the lugs, hidden by the bracelet, or worn down by polishing.
What does 750 mean on a Rolex?
750 means the gold is 750 parts per thousand pure, or 75 percent gold, which is 18 karat. Every gold Rolex alloy, including yellow gold, white gold and Everose, is 18k. Platinum Rolex watches are stamped 950.
What is the Helvetia hallmark on a vintage Rolex?
Helvetia's head, the female figure that personifies Switzerland, was the Swiss hallmark for 18k gold before 1995. If you find it inside a gold Rolex caseback, that caseback was hallmarked before the St. Bernard replaced it in 1995.
What does the letter on the St. Bernard hallmark mean?
The small letter on the dog identifies the Swiss assay office that tested the piece. Current offices include G for Geneva, C for La Chaux-de-Fonds, B for Biel/Bienne, J for Le Noirmont, T for Chiasso and Z for Zurich.
Can a hallmark help date a Rolex?
Yes, roughly. A St. Bernard means the case was hallmarked in 1995 or later, and a Helvetia head means before 1995. If the mark doesn't match the era of the serial number, the caseback has probably been replaced.
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