My initial thought was a cast cash of the Qing Dynasty in China, where the reverse has similar markings. However, they aren't on the corners of the square, but rather the sides and there are four (different) characters on the other side. I'll keep looking, but in the meanwhile can you please confirm that it isn't attracted to a magnet? I want to make sure that we are dealing with a copper alloy rather than iron. Thx.
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I dabble with cash coins so am far from an expert but I am unfamiliar with any that have the orientation of the square whole to the characters like yours - so my best guess would be it is not a coin, perhaps a charm.
It hasn't been cast in the traditional method of making cash-style coins - but it's been designed to kind-of-look like it was cast.
This, combined with being made of iron, points me toward it not being an official coin. My best guess: a "funeral coin", designed to be thrown into a funeral fire.
It seems to have the same design on both sides, which also points towards a non-monetary function. I can't tell if the script is Manchu, Arabic, or just random squiggles intended to mimic Manchu. But the lack of Chinese characters implies to me it is not of Chinese or Chinese-diaspora origin. Perhaps from somewhere in Southeast Asia.
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