The legendary Archiduke Joseph Diamond, 76.02 carat D, IF Golconda diamond. Photo Christie's Image Ltd 2012

The unmounted cushion-shaped diamond weighing approximately 76.02 carats, in purple leather fitted box. Estimate on request

Accompanied by report no. 5151001770 dated 14 September 2012 from the GIA Gemological Institute of America stating that the diamond is D colour, Internally Flawless clarity; a letter indicating that the diamond is Type IIa; a GIA monograph and a letter dated 1 October 2012 stating that 'to date the Archduke Joseph Diamond is the largest D-color, Internally Flawless diamond we have graded from the historic Golconda region'. 

Letter dated 12 June 2007 from the GIA Gemological Institute of America stating that 'upon examination, prior to and after re-cutting, we can confirm that the 76.02 carat diamond was cut from the diamond known as the 'Archduke Joseph Diamond''

Report no. 12090150 dated 26 September 2012 from the Gübelin GemLab stating that the diamond is D colour, Internally Flawless clarity, and a Note indicating that the diamond is Type IIa; also with an Appendix stating that the diamond is 'blessed with a purity of colour and high degree of transparency, which are particular to the world's finest natural type IIa diamond (the purest type in terms of chemistry). Diamonds of this type and size, displaying such a superior quality as well as an antique cutting style, are extremely rare and will unequivocally evoke references to the historic term of 'Golconda''

Christie's. Geneva Magnificent Jewels. 13 November 2012, Geneva