White Copper Mountain Ghost Coin Bagua Pendant

The coin is round with a square hole at the centre and a wide rim around the outside. One face carries two characters in heavy strokes that hold the middle, ringed by a band of talismanic writing whose figures run into one another like an unbroken line; the other face carries the eight trigrams, their lines set around the square hole. Both grounds were left with a sand finish, and the characters and trigram lines stand up from it. The rim is wide and thicker than a common coin, with a clear step under the finger, and a fine line runs right around it where the edge was dressed.

This is a charm coin, also called a yansheng coin, and it was never meant to buy anything. Mountain ghost coins form a class of their own within the group: two characters on one face with a ring of thunder-order talisman writing, the eight trigrams on the other. Folk practice hangs one as a protective piece. The Daoist way of drawing a talisman was carried straight onto the copper, so the characters are not quite characters and the talisman is not quite a talisman, and only someone who knows the form can read it aloud. Charm coins come in many kinds — zodiac signs, auspicious phrases, talismans — and the mountain ghost line belongs with the talismans.

Two versions are offered, the plaque alone and one with a leather cord. The cord is dark and matches the aged tone of the copper, its end finished inside a copper clasp, and the length can be adjusted. The plaque alone suits anyone who already has an old cord to put it on. Leather dislikes water: take the piece off to wash your hands, and if the cord does get wet, dry it in the shade rather than near heat. Do not close the copper clasp with pliers, because once crimped it works loose; change it at the same time as the cord.

The lines of a talisman are fine and full of turns, which makes them the hardest thing on the piece to cast. A broken line spoils the talisman, and a smeared one turns the whole ring into a blot. On this piece the lines run continuously, a little thicker at the turns, which is the normal result of the melt pooling in a corner. The trigram face has wider lines and is easier to cast; what is difficult there is keeping even spacing between the eight. Old charm coins were sand cast, the mould discarded after use, one mould to a batch, and batches differ from one another.

The four corners of the square hole are the weak points, and a cord pulling at one spot over years will round them off. To keep the corners, add a soft ring inside the hole. The face is flat and collects fingerprints, so wipe it with a dry cloth. Once white copper darkens, the talisman lines read deeper, which is all to the good — do not go over the whole face with brass polish, because that flattens the lines. The piece is worn on the outside with both faces showing, and marking is only a matter of time.