See how much this rare blue diamond sold for at auction

A large diamond of a rare pink hue fetched $28.55 million on Tuesday, the star lot of Christie’s semi-annual jewellery sale in Geneva, where designer eye candy drew strong prices.

The private Chinese buyer named it the Sweet Josephine following the sale.

The blue gem was reportedly promptly renamed “The Blue Moon of Josephine”, after his seven-year-old daughter, the youngest of his five children.

“Weighing in at 12.03 carats, the ‘Blue Moon” diamond is a simply sensational stone of flawless colour and purity, combined with a superb cushion shape.

Sotheby’s spokesman David Bennett described Wednesday’s Blue Moon diamond as “magical”.

But this wasn’t Lau’s first big diamond purchase.

Auction house Christie’s has sold the largest vivid pink diamond to be offered at auction for a record 28.7m Swiss francs (£19m).

Sotheby’s says experts took five months for an “intense study” of the original diamond, and a master cutter took another three months to craft, cut and polish the stone. Its estimate was $4.7 million-$5.3 million.

Lau is a controversial figure in Hong Kong not just for his purchases of expensive jewelries.

The Blue Moon Diamond was discovered in January 2014 at the historic Cullinan mine in South Africa. It was then cut and polished in NY, a process that took six months and resulted in the vivid blue gem, according to Sotheby.

Nearly all diamonds have tiny traces of non-crystallised carbon – the element from which they are formed. Christie’s had listed the projected sale price at $23m-$28m. And, since the diamond is mounted as a ring, it has also set a new world record for any jewel.

A Cartier diamond and pearl tiara that survived Germany’s sinking of the Lusitania cruise liner one hundred years in the past, together with its Canadian proprietor Marguerite Lady Allan, whose two daughters perished, went for $ 800,000 in heated bidding, doubling the low finish of its estimate.

Rio Tinto’s (NYE:RIO) Argyle mine in Western Australia claims credit for most of the world’s rare pinks and reds.

“Overall, it was an extraordinary evening”, Bennett said.