A visitor looks at a painting during the preview of China Guardian 2013 Spring Auctions in Beijing, capital of China, May 7, 2013. The three-day preview that opened on Tuesday displayed some 3,900 treasures to be auctioned on Friday. [Photo/Xinhua]

Buddha statues are displayed during the preview of China Guardian 2013 Spring Auctions in Beijing, capital of China, May 7, 2013. The three-day preview that opened on Tuesday displayed some 3,900 treasures to be auctioned on Friday. [Photo/Xinhua]

A man looks at jewelries during the preview of China Guardian 2013 Spring Auctions in Beijing, capital of China, May 7, 2013. The three-day preview that opened on Tuesday displayed some 3,900 treasures to be auctioned on Friday. [Photo/Xinhua]

A visitor takes photos of a painting during the preview of China Guardian 2013 Spring Auctions in Beijing, capital of China, May 7, 2013. The three-day preview that opened on Tuesday displayed some 3,900 treasures to be auctioned on Friday. [Photo/Xinhua]

People visit the preview of China Guardian 2013 Spring Auctions in Beijing, capital of China, May 7, 2013. The three-day preview that opened on Tuesday displayed some 3,900 treasures to be auctioned on Friday. [Photo/Xinhua]

People look at exhibits during the preview of China Guardian 2013 Spring Auctions in Beijing, capital of China, May 7, 2013. The three-day preview that opened on Tuesday displayed some 3,900 treasures to be auctioned on Friday. [Photo/Xinhua]

An exhibitor arranges a jade work during the preview of China Guardian 2013 Spring Auctions in Beijing, capital of China, May 7, 2013. The three-day preview that opened on Tuesday displayed some 3,900 treasures to be auctioned on Friday. [Photo/Xinhua]

A woman looks at jewelries during the preview of China Guardian 2013 Spring Auctions in Beijing, capital of China, May 7, 2013. The three-day preview that opened on Tuesday displayed some 3,900 treasures to be auctioned on Friday. [Photo/Xinhua]

A man visits the preview of China Guardian 2013 Spring Auctions in Beijing, capital of China, May 7, 2013. The three-day preview that opened on Tuesday displayed some 3,900 treasures to be auctioned on Friday. [Photo/Xinhua]

A chinaware is displayed during the preview of China Guardian 2013 Spring Auctions in Beijing, capital of China, May 7, 2013. The three-day preview that opened on Tuesday displayed some 3,900 treasures to be auctioned on Friday. [Photo/Xinhua]