Assay Cards and Certificates: What They Prove and What They Do Not
A sealed assay card ties a specific bar to a certificate of weight and purity. Breaking the seal does not change the gold, but it can change what a buyer will pay.
Many small minted bars are sold sealed into a tamper-evident plastic card printed with the bar's weight, fineness and serial number. The card is a chain-of-custody document: it links that specific bar to a specific assay.
Key takeaways
- An assay card links one bar to a certificate of weight, purity and serial number.
- The seal is tamper-evident, so an intact card shows the bar has not been swapped.
- Breaking the seal does not change the metal, but many buyers pay less for a bar out of its card.
- A card is not proof against a sophisticated counterfeit of both bar and card.
We do not sell bullion
Vanhess is a jewellery shop in Coquitlam, British Columbia. We sell solid gold jewellery. We do not sell, buy or broker bars, coins, ingots or wafers, and we are not a bullion dealer or a financial advisor. This page explains how bullion works so you can compare it fairly with jewellery. It is not a recommendation to buy anything.
What the seal is actually doing
The value of an intact assay card is not the printing. It is that the bar inside has not been separated from its certificate since it left the refiner. Once you open it, that chain is broken, and a buyer now has to take your word that this bar is the one the certificate describes.
That is why sealed bars generally resell more easily. Nothing about the gold has changed, but the friction of proving it has.
| Sealed in the card | Out of the card | |
|---|---|---|
| Metal content | Unchanged | Unchanged |
| Chain of custody | Intact | Broken |
| Ease of resale | Higher | Lower, may require testing |
| Typical buyer reaction | Accepts the certificate | May discount or test |
Be careful
Do not open a sealed bar out of curiosity. There is no upside, and the downside is a slower or cheaper sale later.
What a certificate does not prove
A certificate proves what the refiner said about the bar. It does not independently prove the metal is genuine, because a counterfeiter capable of producing a convincing bar is also capable of producing a convincing card. Documentation raises the bar for a fake, it does not make one impossible.
The real protection is buying from an established dealer with a trading history and a published buy-back price, because they carry reputational risk on every bar they sell.
Frequently Asked Questions
Should I open a sealed gold bar?
No, unless you have a specific reason. Opening it does not change the metal, but it breaks the link between the bar and its certificate, and many buyers will either discount an unsealed bar or want it tested before they buy.
Does an assay card guarantee a gold bar is real?
It certifies what the refiner determined about that bar, and an intact tamper-evident seal shows the bar has not been swapped since. It is not absolute proof, because a capable counterfeiter can fake packaging as well as metal. Buying from an established dealer matters more than the card alone.
Do gold coins come with certificates?
Bullion coins usually do not need one, because the coin's own design, dimensions and security features carry the same information. Collectable and proof coins are more often sold with certificates and presentation packaging.