The symmetrical Tortoise with head poking out, front claws showing, top with hexagon pattern, tail wrapped, standing on an uncarved seal base (the original seal possibly cut off), the jade an impure putty colored nephrite with extensive darker granular areas, pitted and aged. A fine example in the Han dynasty style and likely with some age on it. Other views here. According to the Hanguan Yi (Rites of Han Officials) the Tortoise knop was reserved for the exclusive use of generals.