How to Read a Silver Assay Card and Spot a Fake

Most guides on assay cards are written to sell you bullion, and they tend to blur the assay card together with the certificate of authenticity until neither is clear. This one sells nothing. Here is exactly what an assay card is, what every field on it means, how to verify the serial number and seal, and the question dealers skip: whether you should ever break it open.

What Is a Silver Assay Card?

A silver assay card is a sealed, tamper evident package that certifies a bar's weight, purity, and metal content, tying it to a unique serial number. The card encases the bar in clear plastic so you can see it, and printed on the card is the technical record proving the metal inside is exactly what the refiner claims.

The word assay refers to the analysis that verifies a metal's purity, a process so old there is a reference to it in the Bible. When a refiner assays a silver bar, confirms it meets its stated fineness, and seals it with a card documenting the result, the buyer gets proof of purity and authenticity in one package. This is why bars sold in intact assay cards, like most of those from PAMP, are trusted on sight and often sell more easily than loose bars.

Not every silver product comes with one. Assay cards are most common on bars, especially smaller ounce sizes, while larger bars may ship with a separate assay certificate instead. Knowing how to read the card, and how to tell it apart from a lesser document, protects you whether you are buying or selling.

What Information Is on an Assay Card?

Every genuine assay card carries a specific set of details, and knowing what each one means lets you read the card at a glance. A complete card lists the metal type, weight, purity, serial number, refinery name, and the assayer's signature or stamp.

• Metal type and weight. The card states the metal (silver) and the exact weight, such as 1 oz, 10 oz, or 1 kilo, so there is no ambiguity about what you hold.
• Purity or fineness mark. Investment silver almost always shows .999, meaning 99.9% pure, and premium bars may show .9999. This fineness mark is the core of the guarantee.
• Serial number. A unique identifier assigned to that individual bar. It appears on the card and, on most bars, stamped on the metal too, linking the two together.
• Refinery or mint name. The producer, such as PAMP Suisse or the Royal Canadian Mint, clearly stated and usually stamped on the bar as well.
• Assayer's signature or stamp. The mark of the expert who verified the bar met the refinery's requirements before it was sealed.
• Dimensions and date. Some cards add the bar's dimensions and the date of production or assay, giving you more detail to match against the physical bar.

These fields do more than decorate the package. Each one is a data point a dealer checks when you sell, which is why an intact card with matching details makes a bar faster and easier to move. To see how the stated weight and purity translate into actual silver value, our silver bar calculator turns those figures into a melt value at the current spot price.

Assay Card vs Certificate of Authenticity: What's the Difference?

This is the distinction almost every guide muddles, and getting it right matters. An assay card seals the bar and proves its purity through testing, while a certificate of authenticity confirms an item is genuine but does not test purity and does not seal the product.

In short, an assay card is proof of purity; a COA is proof of authenticity. Both add confidence, but the assay card is the stronger document because it comes from a testing process and physically seals the metal. If you are offered a COA on a bar, it is reasonable to ask whether an assay card or certificate exists too. And if a bar has neither, that is not automatically a problem, as we will cover below.

How to Verify a Silver Assay Card Is Genuine

A card only protects you if it is real and matches the bar it seals. The most important check is that the serial number on the card matches the serial number stamped on the bar. A mismatch is a clear signal to stop and verify before buying.

• Match the serial numbers. Compare the number on the card to the one on the bar. They should be identical. If the bar has no number, or the numbers differ, treat the product as unverified until you confirm it.
• Confirm the refinery name appears twice. The producer's name should be stamped on the bar and repeated on the card. Recognized names like PAMP, RCM, and Asahi follow consistent formats.
• Inspect the seal. The packaging should be intact and tamper evident, with no signs of having been opened and resealed. A broken or crude seal is a warning.
• Check the details against the physical bar. Weight, dimensions, and fineness on the card should match what you can measure and see. Genuine bars match their published specifications precisely.
• Buy from reputable sources. The single best protection is purchasing from established dealers and refiners that are LBMA members or COMEX deliverable, rather than unknown sellers or auction listings.

The card supports the bar's identity, but it does not replace checking the metal itself. For the hands on tests that confirm a bar is solid silver rather than a plated fake, our guide on how to test silver covers weight, dimension, and magnet checks in detail.

Should You Break the Assay Card Seal?

Here is the question dealer guides rarely answer straight, because the honest answer works against handling the metal. Breaking the seal on an assay card usually lowers the bar's resale value, so most owners leave sealed bars sealed.

An intact assay card is part of what makes a bar easy to resell. It carries the serial number, the purity guarantee, and the tamper evident seal that tells the next buyer the bar has not been touched since it left the refinery. Break that seal and you remove some of that assurance, which can mean a slightly lower offer or extra verification when you sell. Bars kept in their original sealed packaging typically command a small premium over the same bar loose.

That said, the seal is not sacred. If you simply want to hold your silver, or you are melting or selling to a refiner who assays the metal themselves, the packaging matters far less. The rule of thumb: if you might resell to another investor or dealer, keep the seal intact; if the bar is destined for a refiner or your own long term storage, the seal is optional. Either way, once you know the weight and purity, our per ounce calculator tells you what the silver itself is worth at today's price.

Which Refiners Include Assay Cards?

Major private refiners and government mints seal their investment bars in assay cards as standard, and the recognized names are the ones whose cards carry the most weight. Buying from these producers is part of why their bars resell so easily.

PAMP Suisse is the classic example, sealing its Fortuna bars in visible assay cards that are recognized worldwide. The Royal Canadian Mint, Asahi Refining, and Sunshine Minting also provide assay documentation on their bars. These are the same names that dominate any discussion of which bars to buy, and the assay card is one reason their products move so smoothly on the secondary market. For a full comparison of these producers and when their premiums are worth paying, see our guide to the best silver bar brands.

Generic bars from smaller private mints may or may not include a card. That does not make them fake or worthless, but it does mean the burden of verification shifts more onto the buyer and the dealer at resale.

What If Your Silver Has No Assay Card?

A missing assay card does not mean your silver is fake or unsellable. Plenty of legitimate silver trades without one. Junk silver coins, older bars, generic rounds, and secondary market pieces frequently have no card at all, and they are bought and sold every day on the strength of the metal itself.

What an assay card does is make verification faster and resale smoother, especially for bars from prestige refiners. Without one, a dealer relies on weighing, measuring, and testing the piece directly, which is routine for them. If you are holding silver with no documentation, the value is still the metal content at the current spot price. Our silver value guide helps you work out exactly what that is by weight and purity, card or no card.

The practical takeaway: an assay card is a convenience and a resale advantage, not a requirement for silver to have value. Buy sealed bars from reputable refiners when you can, keep the cards intact, and understand that uncarded silver is still perfectly real silver.

Common Questions About Silver Assay Cards

Final Thoughts

An assay card is a small package doing an important job: it ties a specific silver bar to a tested guarantee of weight and purity, sealed so the next buyer can trust it. Read one properly and you can confirm at a glance that a bar is what it claims to be, which is the whole point of the document.

The essentials are simple. Match the serial number on the card to the bar, confirm the refinery name and intact seal, keep sealed bars sealed if you plan to resell, and remember that silver without a card is still real silver worth its metal content. Buy from reputable refiners, verify before you pay, and whether your silver is carded or not, know its melt value before any transaction so you always negotiate from a real number.