The 59.60 carat Pink Star diamond. the most expensive gemstone in the world.

The Pink Star diamond last week became the most expensive diamond ever sold at auction.  Gem dealers had been looking at the sale, conducted by Sotheby’s, with a mixture of excitement and apprehension.  The excitement because of the quality of the stone: it is the largest pink diamond of its kind ever to be graded by the GIA.  The fabulous gemstone ticked every box: it is internally flawless and has been given the classification of Fancy Vivid Pink, the most sought after in coloured diamonds.  The icing on the cake for the stone was its designation as a Type IIa, meaning it is a chemically pure stone- a designation only given to 2% of gem quality diamonds.

The hammer comes down on the Pink Star diamond at Sotheby's Hong Kong.

Failed to sell: the Shirley Temple Blue diamond.

The apprehension came from the stone’s recent chequered history.  The stone had been auctioned relatively recently, in 2013, achieving a hammer price of $83 million- but the buyer defaulted on payment.  There has also been speculation recently on whether the eye watering amounts being fetched in the last few years by large coloured diamonds is sustainable.  After all, there aren’t that many people in the word who can afford such things, and within that clientele not all are interested, which makes the potential client base very small indeed.  The flop that was the sale of the Shirley Temple blue diamond was something Sotheby’s was anxious not to repeat again.  The prices achieved at auction for important coloured diamonds are the benchmark by which the industry sets the prices, so with colourless stones experiencing something of a lacklustre period at the moment diamond dealers were hoping for a whopper to underpin asking prices.

The stone was bought by the jewellery retailer Chow Tai Fook, who was bidding by telephone, who has renamed it the CTF Pink.  It is the stone’s third rechristening: it was originally named the Steinmetz Pink, after the group who bought the 132.5 carat rough gem.  They spent a cautious 20 months cutting and polishing the stone, unveiling the finished 59.60 carat gem in all its glory at a ceremony in Monaco.