Authenticity and sourcing

The value of physical bullion depends entirely on its authenticity. A coin or bar that is not what it claims to be has no investment value, regardless of how convincing it appears. This page explains how authenticity is established in the bullion market, what purity standards mean, the role of recognized mints and refiners, and what to look for when purchasing.

Purity standards

Investment-grade bullion is sold to specified purity standards, expressed as a decimal fineness. The fineness indicates the proportion of the product that is the named metal, with the remainder consisting of trace alloys or impurities. Common standards include:

• Gold: .999 (three-nines fine) or .9999 (four-nines fine, sometimes called “four nines”). Investment-grade gold in Canada must meet a minimum of .995 to qualify for GST/HST exemption.
• Silver: .999 or higher. The Canadian threshold for investment-grade silver is .999 minimum.
• Platinum: .9995 or higher.
• Palladium: .9995 or higher (though as noted in Tax Treatment in Canada and the US, palladium is taxed in Canada regardless of purity).

Higher fineness is not necessarily better as an investment. A .9999 gold coin and a .999 gold bar both contain effectively the same gold content per ounce — the small difference in fineness reflects refining process variation rather than meaningful difference in metal content. Fineness primarily indicates that no significant impurities are present.

Assay marks and certification

Authentic bullion bars and coins are stamped or printed with identifying marks that allow them to be traced back to their producer and verified. These marks typically include:

• The mint or refiner name (or logo)
• The product’s weight, expressed in troy ounces or grams
• The fineness (e.g., .9999 for four-nines gold)
• For bars, a unique serial number specific to the individual piece

Bars are commonly sold in tamper-evident assay cards — sealed plastic sleeves that include a certificate of authenticity issued by the refiner. The assay card itself is part of the bar’s value: a bar removed from its assay packaging requires re-verification before resale, which can affect both price and ease of selling. Coins, by contrast, do not require external assay packaging because their identifying marks are struck directly into the metal as part of the minting process.

Recognized mints and refiners

A small number of internationally recognized mints and refiners produce the majority of investment-grade bullion. Their products trade at a premium over generic bullion because of trust: a buyer can rely on the producer’s reputation and the industry’s acceptance of their products without needing to independently verify each purchase.

The most important credential in this market is LBMA accreditation. The London Bullion Market Association is the global standard-setting body for precious metals refining. LBMA-accredited refiners must meet rigorous standards for assay accuracy, financial stability, and ethical sourcing, and their products are accepted across the secondary market without re-assay. The “Good Delivery List” — the LBMA’s roster of accredited refiners for gold and silver — is the de facto international standard.

Sovereign mints — including the Royal Canadian Mint, United States Mint, Perth Mint, and Royal Mint — produce coins under government authority and are universally recognized. Sovereign coins are accepted in secondary markets globally and typically command premium prices over generic bullion of the same metal content.

Bullion from mints or refiners outside this recognized circle may still be authentic, but its resale liquidity is generally lower. Secondary buyers may require independent verification before purchasing, which can affect both price and ease of selling.

Counterfeits and how the industry addresses them

Counterfeit precious metals are a real issue in the global market, and prospective buyers should understand the landscape — though the existence of counterfeits should not deter purchasing from the legitimate market, which has effective safeguards in place.

Counterfeits typically fall into a few categories:

• Replica branded bars and coins. Counterfeit pieces stamped with the markings of well-known mints or refiners (PAMP Suisse, Royal Canadian Mint, etc.) but produced from base metals or substantially lower-purity material.
• Tungsten-filled gold bars. Tungsten has a density very close to gold, making it the most common substitute used to fake larger gold bars. Counterfeit tungsten-cored bars have appeared in international markets, sometimes with the gold layer thick enough to defeat surface tests.
• Plated coins. Counterfeit silver and gold coins struck from base metals (often a copper or zinc core) and plated with a thin layer of the precious metal. Common in lower-cost counterfeits sold through unregulated online marketplaces.

The industry mitigates these risks through several mechanisms:

• LBMA accreditation and chain-of-custody. Refiners on the LBMA Good Delivery List operate under strict assay and recordkeeping standards. Bars from accredited refiners are tracked through wholesale channels.
• Sovereign mint security features. Modern coins from major sovereign mints incorporate anti-counterfeiting features — micro-engraved details, radial lines, security marks, and other elements that are difficult to replicate without specialized equipment.
• Tamper-evident assay packaging. Sealed assay cards include unique serial numbers and packaging that cannot be opened without visible damage. A bar in intact assay packaging is significantly harder to counterfeit at scale than a loose bar.
• Dealer authentication. Reputable dealers source new product directly from mints and authorized wholesalers, and test secondary-market product before resale using methods such as X-ray fluorescence, ultrasonic verification, specific gravity testing, and visual inspection.

The practical consequence is that buyers who purchase from established dealers and stick to recognized mints and refiners face very low counterfeit risk. Counterfeit issues are most common in private-party transactions, unregulated online marketplaces, and purchases of unbranded or unrecognized products.

How gold is tested

No single test proves a coin or bar is genuine. Professionals combine several checks, starting with the ones that cannot damage the metal.

• Weight and dimensions. Every mint publishes the exact weight, diameter and thickness of its bullion products. A precise scale and calipers will catch many fakes, because a base metal of the same size weighs a different amount. Tungsten is the exception: its density is close to gold’s, which is why it is used in fake bars.
• Look and sound. Compare the design, lettering, edge and security features with a known genuine piece. Many genuine gold and silver coins also give a clear, long ring when gently tapped, while base metals sound dull. These are useful warnings, not proof.
• Magnet. Gold and silver are not magnetic, so a coin that sticks firmly to a strong magnet is not genuine. A coin that doesn’t stick has not passed anything: many fakes are not magnetic either.
• X-ray fluorescence (XRF). A dealer’s XRF analyzer reads the metal’s composition in seconds without damage. It measures the surface, so a thick plating can hide a different core.
• Ultrasonic and electrical tests. These look beneath the surface to detect a core of a different metal, the usual way to check larger bars without cutting them.
• Acid and fire assay. Acid testing scratches the item and leaves a mark, and fire assay melts a sample. They are accurate, but they damage the piece, so they are used on scrap and jewellery, not on bullion you want to keep or resell.

At MintedMarket, we use X-ray fluorescence (XRF) and an electromagnetic tester to verify metal without damaging it.

What to look for at purchase

When buying physical bullion, expect to receive:

• Products in their original mint packaging or assay card, intact and undamaged
• Visible mint, weight, and fineness markings
• A clear product description from the dealer specifying mint, weight, and purity
• For bars, a verifiable serial number where applicable
• For graded coins, the original third-party grading service slab (see Coin Grading Explained)

Damaged packaging, missing or unclear marks, vague product descriptions, and prices significantly below market without explanation are all warning signs. When in doubt, purchase from established dealers with documented sourcing rather than from informal channels.