Manufacturing Techniques of Gilt-copper Crown Ornament with a Bird Wing-shaped Decoration Excavated form Ancient Tomb in Imdang, Gyeongsan

Abstract

The ancient tombs in Imdang of Gyeongsan, a representative historic site of Silla culture, are a group of ancient tombs built by local powers of Silla during the Three Kingdoms Period which existed fragmentarily in written records as the tomb of the ruling class in Apdokguk(押督國). In the ancient tomb Imdang 1A, where the appearance at the time of the burial was confirmed, the gilt-copper crown ornament with a bird wing-shaped decoration was excavated showing the relationship between the central Silla and the ruling powers in the local provinces. This the gilt-copper crown ornament with a bird wing-shaped decoration was produced in the order of ① cutting and making of each component, ② carving circular patterns, ③ gilding, ④ joining the front and wing ornament, ⑤ punching for wire connection, ⑥ attaching the spangles. The front, wing ornament and circular spangles(Dalgae) were made with a thin copper plate, and the front and wing ornament overlapped each other with a size of about 5 mm. And it was jointed with three metal rivets with a square cross section. The circular patterns, carved on the border between the front and wing ornament, was carved in the shape of a circular dot by chiseling in the vertical direction with a round-tip carving tool. The gilt-copper wire used to connect the spangles(Dalgae) was first thinned by hammering. After that, thinner and more uniform wires in thickness was drawn using the drawing technique. The gilt-copper wires were inserted into the spangles(Dalgae) and twisted three times so that they were of similar length. The wing ornament and circular spangles were gilded with a thickness of 3 to 5 µm, and the gilded layer of the wire was the thinnest at 1 to 4 µm. To manufacture the gilt-copper crown ornament with a bird wing-shaped decoration, the form was made with copper as the basic material and the surface was gilded with the amalgam gilding technique that mixes gold and mercury.