One of the world's largest diamonds, a pear-shaped 110.3-carat yellow rock, will go under the hammer in Geneva in November expecting to fetch about $15 million, an auction house said Thursday.

The Sun-Drop diamond, discovered in South Africa last year, is billed by Sotheby's as the "world's largest known pear-shaped fancy vivid yellow diamond".

"This stone has immense presence and is truly stunning. It is also one of the largest diamonds ever to have appeared at auction," Sotheby's Switzerland co-chairman David Bennett told a news conference in Hong Kong.

The Chinese city, which has emerged as the world's third-largest auction centre after New York and London, was the first stop of an international tour on which the precious stone is being showcased before the November 15 auction.