 | A blue diamond weighing 12.03 carats and described by experts as internally flawless could sell for a record $55 million (47 million euros) when it goes up for auction in November, Sotheby’s said Thursday. |  The first "window" is open in the diamond. It is from this first facet that the other ones will be built from. |
 Cullinan diamond mine ore train | The Blue Moon diamond, discovered in South Africa in January last year, will be exhibited in Hong Kong, London and New York before its likely purchase at auction in Geneva on November 11, 2015. The Cullinan mine produces the most type II diamonds of any mine on earth. In 2014 it yielded the Blue Moon as well as a 122.52 carat type IIb light blue diamond and a 232.08 ct type IIa colorless diamond. The largest rough diamond of all time was discovered at the Cullinan mine in 1905. |  |
 | The Blue Moon was cut from a 29.62-carat rough diamond unearthed at the Cullinan mine in January. The mine is known for producing blue diamonds, but these gems still account for less than 0.1 percent of its total diamond output. The Blue Moon diamond drew widespread media attention when the discovery of the 29.62 ct rough at the Cullinan mine was announced in January 2014. This mine, formerly known as the Premier, is also the source of the historic Cullinan diamond, as well as two other important blue diamonds: the Smithsonian Institution’s Blue Heart, a 30.62 ct Fancy Deep blue gem discovered in 1908, and the 27.64 ct Fancy Vivid blue Heart of Eternity, unveiled by Steinmetz in 2000. |
 |  The Heart of Eternity, fancy vivid blue diamond |
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