Authenticate your 1 oz Gold American Buffalo

How to spot a fake American Gold Buffalo

The American Gold Buffalo was the U.S. Mint's first .9999 fine (24-karat) gold coin, introduced in 2006 with James Earle Fraser's 1913 Buffalo Nickel design. Because it's pure gold and widely traded, it's worth faking. Simple plated fakes are easy to catch; tungsten-core fakes are harder, so combine several checks rather than relying on one.

What fakes look like

Gold-plated base metal

Brass, copper or another base metal with a gold plating. No common base metal is as dense as gold, so these are usually the wrong weight, the wrong size, or both.

Tungsten-core fakes

A tungsten core inside a gold shell or plating. Gold is about 19.3 g/cm³ and tungsten about 19.25 g/cm³, so a well-made one can hit the right weight, size and specific gravity. Because the outside is real gold, surface tests such as acid or a quick XRF reading can also pass.

Struck copies

Fakes struck from counterfeit dies, in any of the materials above. Detail ranges from crude to convincing.

The checks, in order

1. Weight

A genuine 1 oz Gold Buffalo contains one troy ounce of .9999 gold, so it weighs about 31.1 g. Use a scale that reads to 0.01 g. Anything more than a few tenths of a gram off is a strong sign of a fake.

Note that the Buffalo is pure gold, unlike the 22-karat Gold Eagle (33.93 g), so don't compare it to an Eagle's weight. A correct weight doesn't rule out a tungsten fake.

2. Diameter and thickness

Measure with digital calipers and compare to the facts box on this page. A fake that gets the weight and diameter right but not the thickness points to a metal of the wrong density. Measure thickness in a few places to catch an uneven coin.

3. Magnet

Gold isn't magnetic. Any attraction to a strong neodymium magnet means the coin is fake. Tungsten, brass and copper aren't magnetic either, so passing only rules out steel-cored fakes.

4. The ping test

Tap the coin gently while it's balanced on a fingertip or hung on a thread. A genuine Gold Buffalo rings with a clear tone. A coin's resonant frequencies depend on its size and on the stiffness and density of the metal. Tungsten is several times stiffer than gold, so a tungsten core changes how the coin rings even when the weight is right.

The ping test at the top of this page compares the coin's sound with the frequencies a genuine Gold Buffalo should produce. It's one of the few home tests that responds to what's inside the coin and not just its surface, which makes it a useful check against tungsten. It can still miss some fakes, and it can be thrown off by background noise, how you hold the coin, damage, or a capsule. If you get an unexpected result, take the coin out of its capsule, retest somewhere quiet, and back it up with the other checks.

5. Design detail

Use a 10x loupe and compare against official U.S. Mint images.

Obverse (Native American portrait):

• Sharp, well-defined hair and feathers
• LIBERTY and the date cleanly struck and correctly placed

Reverse (American bison):

• Detailed fur texture, especially on the shoulder hump
• UNITED STATES OF AMERICA, E PLURIBUS UNUM, the $50 face value and the weight and fineness inscription all crisp and evenly spaced
• A natural-looking mound under the bison

Common red flags:

• Mushy or blob-like hair and fur
• Wrong letter weight or spacing in the inscriptions
• An overall soft or greasy look

6. Color

Pure gold has a rich, buttery yellow color. It's noticeably less orange than 22-karat coins like the Gold Eagle or Krugerrand. A coin that looks too orange, too pale, or has a greenish tint deserves a closer look. Color is subjective, so this works best side by side with a coin you know is genuine, under natural light.

7. Edge

The Gold Buffalo has a reeded edge. Under a loupe, check that the reeds are even, sharp and run all the way around. Watch for:

• Irregular spacing or shallow, mushy reeds
• A seam or join line around the edge, which can indicate a core inside a gold shell

8. Specific gravity and professional testing

Specific gravity (weighing the coin in air and then suspended in water) should come out close to 19.3 for pure gold. It's a good check against plated base metal, but it won't catch tungsten, because tungsten's density is so close.

A conductivity meter such as a Sigma Metalytics verifier reads below the surface and is a good check for a tungsten core. Many dealers have one. A professional assay is the final word.

Versions that need extra care

• Proof coins (struck at West Point) have mirror fields, frosted designs and a "W" mint mark. They sell at a premium, so buy them in original Mint packaging or a verified PCGS or NGC holder.
• Fractional sizes and special issues were struck in smaller numbers than the 1 oz bullion coin. They have their own weights and sizes, so don't test them against the 1 oz figures.

Fake grading holders exist. Always look up the certificate number online and check that the coin in hand matches any database photo.

Where risk is higher

Fakes most often come through sellers you can't hold to account: unknown or overseas marketplace accounts, social media listings, and private sales. A price at or below the gold spot price is a strong warning sign. Buying from an established dealer with a return policy greatly reduces the risk.

If you suspect a fake

1. Stop. Don't sell it on or trade it, even with a warning.
2. Test further. Repeat the weight, dimension and ping tests carefully, then ask a dealer to check it with a conductivity meter, or get an assay.
3. Document it. Photograph the coin, your measurements and your purchase records.
4. Contact the seller. Ask for a refund. If that fails, use your marketplace or card dispute process.
5. Report it if you think a seller is knowingly dealing in fakes. In the U.S., counterfeits of U.S. coins can be reported to the Secret Service.

For comparison with the 22-karat Eagle, see how to spot a fake Gold Eagle.

Quick checklist

• Weight close to 31.1 g
• Diameter and thickness match the facts box
• Not attracted to a magnet
• Ping test matches a genuine coin
• Sharp detail on the portrait and the bison
• Buttery yellow color, not orange or pale
• Even reeding with no seam on the edge
• Realistic price, reputable seller