White diamond sold for record $30.6 million at Sotheby's Hong Kong auction

The 118 carat white diamond is the largest and most significant such stone graded by the Gemological Institute of America

A White diamond has fetched a record $30.6 million at a Sotheby's auction in Hong Kong

A white diamond the size of a small egg has fetched a record $30.6 million (£19.3m) at a Sotheby's auction in Hong Kong on Monday night.

The 118.28 carat oval white diamond is the largest and most significant such stone graded by the Gemological Institute of America.

Sotheby's, who held the auction as part of their Autumn art and collectibles sales, said the gem was discovered in South Africa and weighed 299 carats before cutting, but refused to specify the country because the seller wished to remain anonymous.

Two phone bidders battled to win the precious gem in a six minute bidding war, until one dropped out.

The “flawless” white oval diamond, mined and cut two years ago, was hammered down to $27.3m (£16.98m), just under the low end of the $28 million to $35 million estimate range set by Sotheby's. Total price including commission came to $30.6m. The sale price beats the previous record of $26.7m (£16.6m) for a white diamond set in May this year.

The auction's other highlight, a 7.6 carat flawless, round, vivid blue diamond which had an estimate of $19m (£11.8m) failed to reach its reserve price.

The two gems were among 330 lots of rare jewellery on auction sold for a total of $95 million (£59.1m) - $15 million less than expected.

“Hong Kong has in the last few years pulled itself up alongside Geneva and New York as one of the three major selling centres at auction” for diamonds, said Quek Chin Yeow, deputy chairman of Sotheby's Asia and an international diamond expert.

That record could be beaten when Sotheby's puts a pink 59.60-carat diamond on auction in November, which is expected to fetch more than 60 million dollars (£37 million) in Geneva.