Weighing 59.60 carats, the oval-cut stone – mounted on a ring – is reportedly the largest flawless or internally flawless, fancy vivid pink diamond that the Gemological Institute of America (GIA) has ever graded. The Pink Star is also Type IIa, which is rare for a pink diamond of its size and colour.
“The GIA laboratory has been issuing grading reports for 50 years and this is the largest pink diamond with this depth of colour that we have ever characterised,” GIA senior vice president Tom Moses told the Financial Times.
The diamond is part of Sotheby’s Magnificent Jewels auction, which will be held in Geneva on Wednesday 13 November.
According to Sotheby’s, the Pink Star is more than twice the size of the Graff Pink – the 24.78-carat pink diamond that currently holds the world auction record for any gemstone or jewellery item.
The Pink Graff sold for CHF 45.44 million (A$53.3m), and the Pink Star is expected to sell for more than $64 million.
And in other coloured diamond news, UK-based Gem Diamonds has discovered a rare 12.47-carat blue diamond at its Letšeng mine in Lesotho.
While the company’s statement did not comment on the blue stone’s quality, it is expected to “fetch good prices” at Gem Diamonds’ tenders held in Antwerp.
The value of blue diamonds was evident earlier this year when a 5.3-carat fancy deep blue diamond sold at auction for £6.2 million (A$10.5m), setting a per-carat record for a diamond that colour.
Gem Diamonds owns 70 per cent of the Letšeng mine, with the remaining 30 per cent controlled by the government. The mining company also owns the Ghaghoo mine, currently in development in Botswana.
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