How We Authenticate Coins — Chữ Nôm
Chữ Nôm was the written language of Vietnam before the adoption of Latin characters with tonal marks (Chữ Quốc Ngữ). It was similar to, but distinct from written Chinese. For example, the calligraphy of the character 通 (thông) usually a bit different (on coins at least) -- the stroke to the far left is straighter on Vietnamese coins and tends to zig-zag on Chinese ones. If a coin has Chinese-style characters, chances are it's from China (big surprise, I know)!
In fact there may be some exceptions to this, as Chinese merchants sometimes counterfeited Vietnamese coins in ancient times, and these entered circulation. However the worth of the coins was from the metal content. So these ended up recognized as normal currency in some cases. These exceptions are not what you see sold to tourists, and in fact might be more valuable due to the interesting story.
The easiest thing to spot, is that most of the fakes on the market have the wrong name on them. For example, you will sometimes see fake coins of Jia Qing (嘉慶) being sold as Vietnamese coins minted under Gia Long (嘉隆) -- the characters look somewhat similar, and the former is often used as a good luck charm in feng shui. So if you want to buy Vietnamese coins from a particular emperor, write down their name on a slip of paper and bring it with you. This is usually enough.
The image below is of a fake Chinese coin being sold as a Vietnamese one:
In the larger featured image above, the coins are all Chinese fakes. There are a few interesting ones -- the bottom left coin reads Qianlong (乾隆). This rhymes with 'coin dragon' in Chinese, so is a common charm in feng shui for good luck. The one in the top left reads 道光, and is used for similar purposes. The three Chinese coins we've mentioned form the basis of a Three Emperors Charm in feng shui. When you pronounce the name of the emperors in sequence, it reads "Money gets home"!
Making these charms is what all the 'fake ' coins are manufactured for in China. They are not intended to be sold as genuine old coins, just as a token of good luck to hang in your home. So as annoyed as I am about all these fakes, I understand that the intent of the manufacturer was honest -- the fault is with the retailers.
In fact I think these are quite a cool tradition, and have bought such charms! Just unfortunate that it is sold in this way. Anyway, once you're familiar with the 'lucky coins' in feng shui, you will recognize them immediately when you see fake "Vietnamese" coins being sold.
Finally, and just for fun, here's a photo of the back of these coins. They have dragons, phoenix, Manchu characters, and even the hexagrams of the I Ching on them. Authentic Vietnamese coins do not have these markings. Notably, with the exception of the Manchu characters, authentic Chinese coins do not have these markings either!
