Blue diamond sells for record sum

The Blue Moon diamond broke records this week, when it sold for the highest amount fetched by any diamond ever in Geneva.

The auction, held by Sotheby's, saw the stone, weighing 12.03 carats, go under the hammer for $48.5 million - over $4 million per carat.

Among the world’s largest known fancy vivid blue diamonds, the Blue Moon boasts "internally flawless clarity and truly outstanding colour", says the auction house.

The sun eclipsed the record set in 2010 by The Graff Pink Diamond, when it sold again at Sotheby's Geneva for $46.2 million, and even the price-per-carat record for any diamond, last set in 2014 by The Zoe Diamond ($3.3 million per carat) at Sotheby's New York.

The Blue Moon Diamond was the star lot in an auction that generated a total of $139 million in sales - just short of the record for the world's most expensive jewellery auction.