Last week an 8.74 carat blue diamond was sold for $5.7 million at Sotheby’s auction in Hong Kong. The diamond was an emerald cut, fancy intense blue with VVS1 grade.

The stone was bought by an anonymous phone bidder with the price escalating at the rate of HK$1 million per bid.

255 lost were sold at the auction. Preferred stones were diamonds and Jadeites. Six bidders competed for a 28.88 carat D-color flawless round diamond. The round diamond ultimately fetched HK$36.5 million. An 18.08 carat Kashmir sapphire and diamond ring sold for HK$11.7 million.

According to Quek Chin Yeow, head of Sotheby’s Jewelry Department and deputy chairman, mainland Chinese buyers featured strongly in the 10 most expensive lots of the auction.

The Times Online notes that government stimulus, soaring Shanghai stocks and the explosive property market in Hong Kong have contributed to making the Chinese tycoon a leading buyer of fine art, wine and fine jewelry.

The Sotheby’s Hong Kong auction lasted for six days. Sales raised HK $1.3 billion, 20% higher than originally expected.