Rare ‘Sky Blue’ diamond goes under hammer in Geneva

The emerald-cut 8.01-carat Sky Blue Diamond is set in a Cartier ring Keystone

A rare blue diamond has been sold for CHF17.1 million ($17.1 million) at a Sotheby’s auction in Geneva. There is strong demand for coloured diamonds, which have reached high prices at jewel sales in the Swiss city this week.

The emerald-cut 8.01-carat Sky Blue Diamond, set in a Cartier ring, was sold on Wednesday for a third more than it fetched in 2012 ($12.8 million), said Sotheby’s international jewellery division director David Bennett.

It had been estimated at $15-25 million. The stone was graded fancy vivid blue, the highest possible colour grading, awarded to barely 1% of blue diamonds submitted to the Gemmological Institute of America (GIA), according to Sotheby’s.

The world record for any jewel sold at auction is for the Oppenheimer Blue, a 14.62-carat blue diamond, sold by Christie’s in May for CHF57.54 million.

Bennet told reporters after the sale that demand for coloured diamonds was still “very healthy”.

“People who want the rarest and the most beautiful are seeking out these rare treasures,” he said.

Pear-shaped

Other Sotheby sales included a step-cut fancy intense pink diamond weighing 17.07 carats, set in a ring, sold to London-based jeweller Graff Diamonds for CHF20.8 million.

Graff also bought a fancy intense pink diamond ring weighing 13.20 carats for CHF16.2 million.

At Christie’s on Tuesday, a pear-shaped pink diamond sold for CHF18.1 million.

However, several historic lots failed to sell. These included a diamond necklace from the Russian crown jewels, commissioned by Catherine the Great (1729-1796), estimated at $3-5 million.