HONG KONG -- The largest diamond ever auctioned off in Asia -- a sparkling, 101.27 carat gem about the size of a pingpong ball -- fetched more than US$6.2 million at Christie's in Hong Kong.

The stone sold Wednesday to a private buyer for HK$48.5 million (US$6.21 million), the auction house said.

Cut from a 460-carat rough, the shield-shaped gem boasts 92 brilliant facets and certified F color. While internally flawless, the stone was rated VVS1 for clarity because of a slight imperfection on the surface that's imperceptible to the human eye.

It is the largest colorless diamond to appear on the auction market in the last 18 years, Christie's said. Only three colorless diamonds of more than 100 carats have appeared at auction. All were sold in Geneva.

Naming rights were granted to the new owner.