Guan Lan, a staff of the Shanghai Min'an Auction Co. Ltd, said that the diamond, light yellow in color, and 17.85 to 19.9 mm in diameter, was originally from South Africa and is a private collection piece.

"Siam Star" has already attracted attention of diamond lovers. Experts said that this phenomenon is closely connected with increasing consumption of diamond on the Chinese mainland.

Statistics show that with annual diamond consumption hitting 20 billion yuan(about 2.5 billion U.S. dollars), the Chinese mainland is ranked by DeBeers, the world's largest diamond company, as the world's fifth largest market of diamond consumption.

Shanghai, as a distribution center of diamond deals, has traded various diamond and diamond powder over 225 million carat in the past five years. Experts predict that Shanghai will become a diamond dealing center by 2010, and the trade volume of diamond will hit three to five billion U.S.dollars. Enditem