How physical investment gold is certified: purity, hallmarks and traceability

Buying physical gold as a store of value only makes sense if what you receive is exactly what you think you are buying: metal of the stated purity, from a recognised refiner, with paperwork that ties it to you. Certification is not fancy packaging. It is what makes a bar or a coin something you can verify and sell without trouble. Here we explain, without unnecessary jargon, how investment gold is certified and what to check before you pay.

1. Why certification matters

Gold is one of the few assets you can hold in your hand and, for that very reason, one of the most exposed to counterfeiting and to pieces of doubtful origin. An uncertified bar is not necessarily fake, but you have to prove its purity and origin every time you want to sell it. You pay for that in discounts, assays and lost time.

Certification does three things that go together: it attests to the purity of the metal, it identifies the refiner that produced it and it documents the traceability of the piece. When all three are there and match up, the gold sells in any wholesale market with no discount for doubts over authenticity. If one is missing, it becomes harder to sell.

2. Purity: 999.9 and what "24 carats" means

The purity of investment gold is expressed in thousandths. The reference standard for investment bars is 999.9, that is, 999.9 parts of pure gold per 1,000: what is colloquially called "four-nines gold". It is equivalent to 24 carats on the traditional scale, where 24 carats represent pure gold and lower figures indicate alloys (18 carats are 750 thousandths, 22 carats around 916).

Purity by product

Not all investment gold has the same fineness, and it is not always a defect. Many historical coins were minted at 22 carats to gain hardness and withstand the wear of circulation; their investment value is still that of the fine gold they contain, not that of the alloy. What matters is knowing the real fineness and the fine-gold content of each piece.

The figure that must never be missing is the fine-gold content: the grams or ounces of pure gold the piece actually contains. That is what determines its value against the market price.

3. The LBMA "Good Delivery" hallmark and accredited refiners

The most relevant standard in the wholesale market is the LBMA "Good Delivery" standard (London Bullion Market Association). It is not a commercial brand, but a list of refiners that meet strict requirements of minimum purity, production consistency and controls on the origin of the metal. A bar produced by a refiner accredited on that list enjoys almost universal acceptance in the professional circuit.

For a small buyer the advantage is very practical: a bar from an accredited refiner is much easier to resell. The buyer does not have to rely on your word alone: they can look the refiner up on the public list, although it is normal for them to check the piece before paying. That is why it is better to choose bars from accredited refiners over anonymous bars or brands that cannot be verified, even if those look slightly cheaper.

A small saving on the purchase price of a bar without recognised traceability usually turns into a bigger discount at the moment of sale. Certification is paid for once; the lack of certification is paid for every time.

Standards on the origin of the metal

Accreditation today covers purity and also where the gold comes from, with responsible-sourcing criteria designed to keep out metal of illicit origin. For you as a buyer, it means less risk that the metal has a dubious origin. What it does not prove is that the person selling it to you owns it: that is what the purchase documents are for.

4. The certificate and the assay card

Investment bars usually come in a sealed blister pack that includes an assay card. The card certifies three things about that specific piece: the weight, the purity and a unique serial number that is also engraved on the bar itself. The seal is part of the guarantee: opening or tampering with it may mean a re-assay before resale.

What must match

• The serial number engraved on the bar and the one printed on the assay card must be identical.
• The weight and fineness stated on the card must correspond to those engraved on the piece.
• The refiner's name must appear both on the bar and in the documentation.

In modern bullion coins the role of the "certificate" is played by the official minting itself: the mint guarantees weight and fineness at the moment of issue, and the standardised design makes counterfeiting harder. In these cases, rather than a paper certificate, the backing is the recognised issue.

5. Traceability and buying "in your name"

The technical certification of the piece is only half the problem. The other half is that the gold is tied to you unequivocally. Here it is worth distinguishing between holding certified gold and holding gold in your name.

Allocated versus unallocated gold

The market speaks of allocated gold when the metal is identified as yours (specific pieces, with their serial numbers, reserved to your ownership) and of unallocated gold when you only hold a claim against a counterparty that is, in practice, a credit. The physical investment gold you buy and store with full traceability is allocated gold: you do not depend on the solvency of a bank or a counterparty to recover it.

Buying "in your name" means keeping the purchase documentation (an invoice identifying the pieces and their serial numbers) that proves you are the owner. That chain (invoice, serial number, refiner's certificate) is what allows you to prove ownership and the lawful origin of the metal in any future sale or before the tax authorities.

For the practical side of buying in Spain (VAT, ways to buy and common mistakes), see our guide to buying physical gold in Spain without making mistakes.

6. How to spot dubious gold and retail investor mistakes

Most problems do not come from sophisticated counterfeits, but from purchases made without checking the basics. These are the most common mistakes:

Mistake 1: Buying without a certificate or assay card

A loose bar, with no sealed blister or assay card, is not useless, but when you come to sell it the cost and delay of proving its purity fall on you. Unless the price clearly makes up for that, it is not the right choice for someone buying to preserve wealth.

Mistake 2: Ignoring the refiner

A bar from an unknown or unverifiable brand is harder to sell. Before buying, check that the refiner can be identified and is recognised in the market.

Mistake 3: Tampering with the seal

Opening the blister to "get a better look" at the piece breaks part of the guarantee and may require a re-assay. The seal is kept intact until the moment of sale.

Mistake 4: Not keeping the purchase documentation

The invoice identifying the pieces by their serial number is the proof of ownership and of lawful origin. Losing it makes resale harder and complicates things with the tax office.

Mistake 5: Mistaking a low price for a good purchase

A price noticeably below the market almost always hides a problem: purity lower than stated, absence of traceability or pieces of dubious origin. In investment gold, an abnormally cheap price is a warning sign, not an opportunity.

7. How Equus Capital operates

At Equus Capital we work only with certified investment gold: metal from accredited refiners, with documented purity, serial number and assay card, or coins from recognised official mints. Every transaction comes with an invoice that identifies the pieces by serial number, so the metal is tied to its owner with full traceability. We also offer secure custody for anyone who would rather not store it themselves, always as allocated gold, with no exposure to a counterparty's solvency. What we want is simple: that the gold you buy is genuine, is in your name and can be sold again without trouble.