The year 2005 marked a century since the discovery of the largest gem diamond ever found: the 3,106 ct Cullinan. Eight decades after it was mined, a team of gemologists conducted the first modern examinations of the two largest diamonds cut from the rough, the 530 ct Cullinan I and the 317 ct Cullinan II, which have been part of the Crown Jewels of England since their presentation to King Edward VII in 1908. This article traces the history of this famous piece of rough and its source, South Africa’s Cullinan (formerly Premier) mine, which has yielded more significant diamonds than any other single locality. It also presents the full details of the examination and grading of these two approximately D-color, potentially flawless historic diamonds.
