Lot 402. An Imperial Green Jade 'wufu wudai tang guxi tianzi bao' Seal, Qing Dynasty, Qianlong Period (1736-1795)Length 5 1/8  in., 13. 1 cm; Width 5 1/8  in., 13.1 cm. Estimate: 1,000,000 - 1,500,000 USD. Lot sold 3,413,000 USD. © Sotheby's

of square form, surmounted by a pair of addorsed dragons, each powerfully carved with bulging eyes and flaring nostrils above long whiskers, the mouth open to reveal its curled tongue between sharp fangs, with two long studded horns extending back over its head along a combed mane with finely incised details, the two scaly bodies tightly intertwined and crouching on their haunches, pierced through the center with an aperture, the seal face carved with the characters wufu wudai tang guxi tianzi bao (Seal of the Seventy-Year - Old Son of Heaven of The Hall of Five Happinesses and Five Generations) and carved in honor of the Qianlong emperor's 70th birthday in 1781, the stone of a gray-green color flecked with paler inclusions.