'Cullinan Blue Diamond Necklace' Commemorates Largest Diamond Ever Mined

In 1910, Thomas Cullinan, then chairman of the Premier Mine in South Africa, gifted an elaborate necklace to his wife Lady Annie Francis Cullinan to commemorate the discovery of the largest gem-quality diamond ever mined.

About five years earlier, on January 26, 1905, Captain Frederick Wells was conducting a standard inspection of the Premier Mine when a glint off the wall of the mine caught his attention. At first, he thought it was a shard of glass that may have been embedded there by a miner as a practical joke. But, then he pulled out his pocket knife and pried the object from the wall.

What he extracted was the now-famous 3,106-carat Cullinan Diamond, which weighed a staggering 621 grams (1.37 pounds) and measured 98mm (3.85 inches) long, 57mm wide and 67mm tall. The chairman sold the diamond to the Transvaal provincial government, which, in turn, presented the stone to Britain’s King Edward VII as a birthday gift in 1907. Wells reportedly received a $10,000 bonus for his discovery.

In February 1908, Joseph Asscher & Co. segmented the Cullinan Diamond into nine major finished stones, each of which was given the name Cullinan and a Roman numeral. Two of the gems are in the British Crown Jewels — the Great Star of Africa (Cullinan I) at 530.4 carats and the Second Star of Africa (Cullinan II) at 317.4 carats. The other seven stones remain in the private collection of Queen Elizabeth II.

Cullinan (1862-1936) was knighted in 1910 in recognition of his contribution to industrial development of South Africa. At about the same time, the chairman presented his beloved wife, Annie (1866-1963), with the Edwardian-style "Cullinan Blue Diamond Necklace" — a feminine and elegant piece set with 243 round colorless diamonds and nine fancy intense blue diamonds. It is said that the nine blue diamonds represent the nine major stones derived from the Cullinan Diamond.

Designed in 9-karat rose gold and silver, the necklace features a detachable double-ribbon bow motif with a dangling pendant that holds the Cullinan Blue Diamond, an oval-cut, natural fancy intense blue diamond that weighs 2.60 carats. The piece's overall diamond total weight is approximately 24.11 carats.

Throughout most of its long history, the Cullinan Blue Diamond Necklace had been bequeathed to the first daughter in each generation of the Cullinan family. That tradition ended in 1992, when Anne Robinson, the great granddaughter of Thomas and Annie Cullinan, sold the necklace to jeweler Stephen Silver, president of Stephen Silver Fine Jewelry, Menlo Park, CA.

The necklace was temporarily exhibited at the Smithsonian in Washington, DC, in 1994, and then formally donated by Silver to the National Gem Collection in 2010. The Cullinan Blue Diamond Necklace is currently displayed at the Janet Annenberg Hooker Hall of Geology, Gems, and Minerals, which is part of the National Museum of Natural History.

The Cullinan Blue Diamond and the the Cullinan Blue Diamond Necklace shouldn't be confused with “The De Beers Cullinan Blue,” the 15.10-carat, step-cut, fancy vivid blue diamond that recently came within a whisker of setting a new world record for the priciest vivid blue diamond ever sold at auction.

Now renamed “The De Beers Blue” the stunner achieved a hammer price of $57,471,960 at Sotheby’s Hong Kong in late April. That was just short of the $57,541,779 achieved by the 14.62-carat “Oppenheimer Blue” at Christie’s Geneva in 2016.

Credits: Cullinan Blue Diamond Necklace image courtesy of Smithsonian / Chip Clark, and digitally enhanced by SquareMoose. The De Beers Blue diamond photo courtesy of Sotheby's.