The highlight of this turquoise-hued bronze sword lies in its blade covered with spot patterns, which are quite special ornaments for swords during that period. The mainstream opinion about the spot embellishment holds that these spots were crafted artificially. It was a customary practice in ancient China to coat ready-made swords with tin in order to improve stiffness. Some sword-makers would put the tin-coated swords through special heat treatment and then artificial erosion, ending up with spots in colors of black alternating dark blue. Though different from each other when observed individually, these spots all together constitute a harmonious and eye-catching visual effect.