An enormous blue diamond unearthed in South Africa in 2014 has been sold at auction for R379-million. The Cullinan Dream is the largest fancy intense blue diamond to be offered on public sale.It is one of four diamonds created by a master cutter from a 122.52-carat rough gem found at Petra Diamond's Cullinan mine.The quartet ranged from seven to 24.18 carats and the largest‚ a cut-cornered rectangular mixed-cut diamond named The Cullinan Dream‚ was auctioned by Christie's in New York on Thursday.Rahul Kadakia‚ Christie's international head of jewellery‚ told Mail Online: "Christie's is proud to have achieved yet another record with the 24.18-carat Cullinan Dream blue diamond‚ which sold for $25‚365‚000‚ in the presence of Mr Mark Cullinan himself‚ the great-grandson of Sir Thomas Cullinan."The Cullinan mine‚ discovered by Sir Thomas Cullinan in 1898 in the Magaliesberg foothills‚ is one of the world's best-known sources for pricey diamonds. In 1905‚ the Star of Africa and Second Star of Africa were discovered there‚ with gems cut from the diamonds used for the British Crown Jewels.Mark Cullinan said: "My great-grandfather would be delighted to see how one of the newest exceptional blue diamonds from the mine he discovered resonates with top collectors in the market today."Tobias Kormind‚ managing director of 77 Diamonds‚ said: "For $25.4-million‚ the buyer ... might just have bagged a bargain. Blue diamonds are rarer than pink diamonds‚ but when a comparable diamond‚ a 24-carat intense pink diamond‚ the Graff Pink‚ sold in November 2010‚ it fetched a handsome $46.2-million."The price is also much lower than the $3.9-million per carat achieved by the Oppenheimer Blue in May 2016‚ which at $57.5-million became the most expensive diamond ever sold at auction‚ and the staggering $4.02-million per carat achieved by the Blue Moon of Josephine in November 2015."The Cullinan Dream went to an unidentified buyer for a hammer price of 50.6 million Swiss francs‚ which excluded fees and the buyer's premium. That obliterated the pre-sale estimate range of between 38 million and 45 million francs.Ehud Laniado‚ chairman of seller Cora International‚ told Mail Online the diamond was particularly rare because of its size‚ "strong hue and dominant even spread of colour"...