seal knob (紐刻) is an art that originated in ancient china and is mainly popular in east asian countries. it focuses or decorates on the head-part or the top-side of a seal. it is a kind of sculpture or mini-sculpture. in china, the utmost important seal of all is the imperial seal carved from the heshibi, a sacred ceremonial jade. it was said that the green jade took the form of a round shape with inscriptions that read "having received the mandate from heaven, may (the emperor) lead a long and prosperous life." (受命於天,既壽永昌) this was said to be written by the primer li si for qin shi huang zhao zheng, the augustus emperor of the chinese empire.