Gold Identifier
Why Bullion Is Different
An unmarked jewelry piece could be almost anything. A Krugerrand cannot. Every genuine bullion coin has an exact published diameter, thickness, gross weight and fine gold content. If a coin matches all four, it is very likely genuine. If it misses any one of them, it is not.
That gives you something jewelry never offers: a specification to measure against. All you need is a digital scale reading to 0.01 g and a set of calipers.
The Major Bullion Coins
| Coin | Country | Purity | Gross weight | Fine gold | Diameter |
|---|---|---|---|---|---|
| Krugerrand (1 oz) | South Africa | 91.67% (22K) | 33.93 g | 31.10 g | 32.77 mm |
| American Eagle (1 oz) | USA | 91.67% (22K) | 33.93 g | 31.10 g | 32.70 mm |
| American Buffalo (1 oz) | USA | 99.99% | 31.10 g | 31.10 g | 32.70 mm |
| Maple Leaf (1 oz) | Canada | 99.99% | 31.10 g | 31.10 g | 30.00 mm |
| Britannia (1 oz) | UK | 99.99% | 31.10 g | 31.10 g | 32.69 mm |
| Philharmonic (1 oz) | Austria | 99.99% | 31.10 g | 31.10 g | 37.00 mm |
| Sovereign | UK | 91.67% (22K) | 7.99 g | 7.32 g | 22.05 mm |
| Half Sovereign | UK | 91.67% (22K) | 3.99 g | 3.66 g | 19.30 mm |
| Panda (30 g) | China | 99.9% | 30.00 g | 30.00 g | 32.00 mm |
Two things worth noticing. First, 22K coins like the Krugerrand and Eagle weigh more than an ounce gross: they contain a full troy ounce of gold plus the alloy. Second, the Philharmonic is noticeably wider and thinner than other one-ounce coins, which is a quick visual identifier.
Minted Bars vs Cast Bars
Minted bars are cut from rolled sheet and struck. They have sharp, square edges, a smooth mirror-like surface, crisp lettering, and usually come sealed in a tamper-evident assay card with a serial number. Common brands: PAMP Suisse, Valcambi, Perth Mint, Credit Suisse, Argor-Heraeus.
Cast bars are poured into a mold. They have rounded, slightly irregular edges, a matte or textured surface, and often visible cooling ripples on the top face. They are usually cheaper per gram because production is simpler. Common in India, the Middle East and among refiners.
Neither is more or less genuine: they are different manufacturing methods. But knowing which one you are looking at tells you what surface finish to expect, and an unexpectedly rough "minted" bar is a red flag.
What to Read on a Bar
- Weight: 1 g, 5 g, 10 g, 1 ozt, 50 g, 100 g, 1 kg
- Fineness: 999.9, 999 or 995
- Refiner name and logo: the brand carries real premium value
- Serial number: must match the assay card exactly
- Assayer's signature or mark on the card
- LBMA Good Delivery status for larger bars. The London Bullion Market Association requires Good Delivery gold bars to assay at a minimum fineness of 995.0 and to contain 350 to 430 troy ounces of gold, so an accredited bar outside those bounds is a red flag in itself.
Spotting Counterfeits
Dimensions are the strongest test
Counterfeiters can match gold's weight using tungsten, which has almost identical density. What they struggle to match is weight and exact dimensions simultaneously. Measure diameter and thickness with calipers against the published spec. A coin that is 0.3 mm too thick is a fake, whatever it weighs.
The ping test
Balance a coin on your fingertip and tap it with another coin. Genuine gold and silver produce a long, clear, high ring that sustains for a second or more. Base metal and clad fakes produce a short, dull thud. Free phone apps analyze the frequency signature; the difference is usually obvious by ear alone.
The magnet slide
Gold is not magnetic, but it is diamagnetic: it resists a moving magnetic field. Tilt a non-metallic ramp, place a strong neodymium magnet on it, and let it slide down over the coin: it should visibly slow. Steel-cored fakes will attract the magnet outright. Tungsten cores will not slow it the same way real gold does.
Visual tells
- Mushy or shallow detail in the design: genuine mint strikes are sharp
- Incorrect font, spacing or lettering compared with reference images
- A visible seam around the edge, indicating two halves joined over a core
- Wrong reeding: count the edge grooves against the published number
- Casting bubbles or pitting on a coin that should be struck
- Color that is too brassy or too red for the stated purity
Ultrasound and conductivity
Dealers use ultrasonic thickness gauges and electrical conductivity testers, both of which read through the whole item rather than just the surface. These catch tungsten cores that pass weight, dimension and XRF checks. If you are buying a kilo bar, insist on one of these.
Photographing Bullion for Identification
Shoot the obverse, the reverse and, importantly, the edge. The edge reveals reeding patterns, edge lettering, and any seam that would betray a clad fake. For bars, photograph the stamped face square-on and capture the assay card and serial number separately. Include a ruler or a common coin for scale. Our photography guide covers lighting and framing.
Premiums: Why Bullion Sells Above Melt
A one-ounce Krugerrand does not sell for exactly one ounce of gold. It sells for spot plus a premium, typically 3–8% for common coins, reflecting minting costs, dealer margin and liquidity.
- Widely recognized coins, Krugerrands, Eagles, Maples, carry lower premiums but sell instantly anywhere in the world.
- Small bars and fractional coins carry higher premiums per gram, since minting costs are spread over less metal.
- Sealed branded bars from PAMP or Valcambi command a premium over generic bars.
- Rare dates and proof strikes can be worth far more than their metal: never scrap a coin without checking its numismatic value first.
Our valuation guide covers the melt-value arithmetic that sits underneath all of this.
Identify Any Coin or Bar From a Photo
Photograph the piece and Gold Identifier names the design, explains the markings and shows what the metal is worth today. Free on iPhone and Android.