In 1958, a gold crown was excavated at Ding Mausoleum, consisting of 13 tombs of the Ming Dynasty. It was made of 518 extremely thin gold threads of 0.2 cm in diameter. On the crown two dragons playing with pearl were carved and each squama was carefully inlaid. The technology of making this crown, is called “Huasi Xiangqian” ,or filigree inlays .