Sotheby's will be presenting a 5.16-carat blue diamond ring in one of the top lots at its five-day auction in April in Hong Kong. The auction is expected to generate over $128 million, and the ring embedded with the pear shaped blue diamond is likely to fetch around $5.8 million. %% The auction house chose to present the blue diamond ring at the auction, following the growing importance of Hong Kong in the global gem and jewellery map. Hong Kong has grown into a centre of some of the biggest auctions in the recent past and is attracting serious jewellery buyers from all over the world. Its closeness to China, another leading market is adding to its market potential. %% Hong Kong's share of international jewellery sales at Sotheby's, increased from 19 percent in 1998 to 34 percent in 2008, reports say, overtaking New York to become its second-largest market after Geneva.