The hexagonal gem with delicately engraved foliage and flora was set as a brooch with diamonds and pearls in 1915 by Cartier. Yesterday's underbidder was the Cartier Museum in Geneva.
At 430 carats, it is the largest emerald ever sold at auction. Bonhams believes that it is the largest recorded emerald carved under the patronage of the Mogul court in India.
Stephen Giles, director of jewellery at Bonhams, said Mogul emperors and rajas vied with one another to possess important gems: 'The ultimate of all jewels were emeralds because they represented the final level of spiritual aspiration and were believed to possess mystical healing powers through their ability to blind snakes and dragons.'
Its more recent owner was Victoria Sackville-West, later Lady Sackville (1862-1936), mother of Vita Sackville-West. It was sold yesterday by a family member.
In New York, a 15th-century Korean dish broke the record for any porcelain after selling for dollars 3.082m ( pounds 2m) at Christie's (estimate dollars 300-dollars 400,000). It also broke the record for any Korean art.