Yesterday’s New York Jewels sale at Christie’s featured an impressive fancy intense blue pear-shaped diamond which sold for $3,544,500 which is about £2.2m (including buyer’s premium).

It was the centrepiece lot in the Christie’s Spring Jewelry season, with the New York sale following the recent sales in Hong Kong and London (report here).

Blue diamond weighing 6.29 carats; photo by Christie's

The blue diamond, pictured right, weighed in at 6.29 carats and was certified by the GIA as a fancy intense blue diamond of natural colour, and internally flawless in clarity.

The purchase price of just over $3.5m was within the pre-sale estimate range of $3.3m to $5.5m, and is equivalent to about $565,000 per carat.

The buyer of the blue diamond was anonymous.

Natural blue diamonds are among the rarest of coloured diamonds; the blue colour is caused by a tiny quantity of boron within the crystal structure – just a few parts per million – whilst a violet-blue occasionally seen in diamonds from the Argyle mine in Australia is thought to be the result of hydrogen.

Blue diamonds belong to the extremely rare Type IIb category of diamonds and are semi-conductors of electricity; an attribute which makes them unique amongst other diamonds.

One of the world’s most famous blue diamonds is the Hope Diamond, a 45.52 carat stone currently housed in the Smithsonian Natural History Museum in Washington.  The Hope Diamond was found in the Kollur mine in the Guntur district of Andhra Pradesh (then part of the Golconda Kingdom) in India in the mid-17th century and its history includes a spell in the French Crown Jewels.  The Hope diamond is said to be cursed.

F colour IF clarity 10.01ct diamond; photo by Christie's

Yesterday’s New York sale also included a pear-shaped F colour, internally flawless (IF) diamond weighing 10.01 carats and pictured left.

The pre-sale estimate for this lot was a range of $200,000 to $300,000, but the actual price realised was $458,500, well in excess of the pre-sale estimate and equivalent to $45,800 per carat.  Christie’s reported that the diamond sold to a US private buyer.

Another eye-catching lot from the New York Jewels sale was an impressive coloured diamond ring featuring a cut-cornered modified rectangular-cut fancy yellow diamond weighing 46.72 carats, flanked on either side by a trillion-cut diamond, mounted in 18k yellow gold and platinum, pictured below.

This lot had a pre-sale estimate of $500,000 to $700,000 and was sold within that range for $602,500, equivalent to $12,900 per carat.

Fancy yellow SI1 46.72ct diamond; photo by Christie's

In total the Christie’s New York Jewels sale offered 184 lots of which 167 (91%) were sold.  The total value of the sale was approximately $11.4m or £7m.

Rahul Kadakia, Christie’s Head of Jewelry, commented, “$11.3m changed hands today in a room buzzing with excitement and almost every lot surpassing its estimate. Following our sales in Hong Kong and London, the auction in New York reaffirmed the strength of the jewelry market.”

With thanks to Christie’s New York for information and images