Metal Square Hole Coin Chain Charm

The round coin with a square hole became the fixed form with the banliang of Qin and stayed in use into the last years of the Qing. Round outside, square within, which folk reading took as heaven round and earth square; whether the mint had that in mind nobody can say for certain, but that explanation has travelled furthest. Others say the square hole was for stringing coins onto a square rod to file the edges, turning the whole string at once, which is the more practical account. Banliang, wuzhu, tongbao — the form ran on with round outside and square inside unchanged, and what changed was the inscription.

The square-holed coins are linked one to the next. Small rings join coin to coin, and the whole thing hangs as a string. The faces carry characters cut shallow, with the rim standing a little higher, so the middle feels hollow under the finger. The length is fixed; to change it you take out rings, and each ring removed shortens it by one, so keep the removed rings for spares. The spacing between coins is even, and it hangs in a straight line without twisting. The characters are in relief, standing up, and can be felt as a rise and fall.

This chain is not money; it is a hanging ornament. It can go on a bag, on keys, on a cupboard door. A hanging thing catches, so on a bag put it at the side rather than beside the zip pull. If the length is wrong, take it apart a ring at a time until it looks right; use two pliers, one to hold and one to open the ring. On keys, choose a short one — long and it tangles with everything else in the pocket. Hang one on a cupboard door and it sounds as the door opens and shuts, not loudly.

The rings are closed one into the next, and the closing joint has a gap that can be opened to take a link out; that is how chains of this kind are made. Once shut, the joint sits slightly out of line, which can be felt and does not affect use. The characters are of even depth, with none of the coins badly blurred; in a whole chain you can pick out a few with a thin rim, which is normal in batch work. Coins with a high rim rock when stacked, and that is not distortion. Held in the hand, a whole chain pulls downward with weight; it is not flimsy.

On a hanging chain the bottom coin wears most, and its rim rounds first. To age it evenly, turn the whole chain end for end now and then. Do not wear it in the bath; water gathers in the ring joints and dries as a pale mark. When it dulls, run a soft cloth along the chain rather than pulling at it; the joints will not take a pull, and open one ring and the whole chain comes apart. Copper does not mind water, but it minds water sitting in the gaps; hung long in a damp place, the joints go green. Wipe link by link rather than bunching it in one hand, which leaves the joints untouched.