The Blue Heart Diamond

Since colored diamonds are so scarce, it is rare to come upon an unusually large or vibrant-colored diamond.  The Blue Heart Diamond is an example of such a diamond due to its large size and beautiful color.  The famous diamond has a story behind its name, an intriguing past, and a grand size, placing it as one of the world’s largest and most famous natural blue diamonds.

Also known as the Unzue Diamond, after the Argentinian Mrs. Unzue who had the precious stone for 43 years, the Blue Heart Diamond’s claim to fame is its stunning rare deep blue color, its heart shape, and its large size: an impressive 30.62 carats.  The Blue Heart is ranked the world’s fifth largest blue diamond, coming in after the Sultan of Morocco, a 35.27-carat fancy grayish blue diamond.

The Blue Heart has been mistakenly dubbed the “Eugenie Blue” in reference to the French Empress Eugenie, although any connection between the two is impossible given the stone was only discovered in 1908. Nevertheless, a French connection can be found, since the blue diamond was cut into the contemporary heart shape by the French diamond-cutting firm, Atanik Ekyanan of Neuilly, Paris sometime between the years 1909 and 1910.

For a while it was believed that the stone originated in India, where many diamonds used to originate from.  However, in recent years it was discovered that the Blue Heart was actually found in South Africa in November 1908. At the time, the magnificent diamond weighed an astounding 102 carats in the rough, and was later cut and polished into the diamond we now recognize as the Blue Heart. After the renowned French cutting firm cut the blue beauty, it was sold to Cartier’s, where it was placed in a corsage called “Lily of the Valley.”

The corsage was bought by Mrs. Unzue where it remained until 1953. The jewelry firm Cleef & Arpels bought the jewel, and it was they who disassembled the corsage and turned the diamond into a brilliant pendant surrounded by 25 colorless diamonds. A European family then purchased the diamond pendant along with the necklace for a total of $300,000. Harry Winston got hold of the precious gem in 1959 and had it set in a platinum ring only to have it sold to Marjorie Merriweather Post.  The Blue Heart stayed with Mrs. Post until the 1960s when she decided it was time to donate the treasure to the Natural History Museum at the Smithsonian Institution in Washington DC where it has been on display till this very day. The Blue Heart Diamond is located in the Janet Annenberg Hooker Hall of Geology, Gems, and Minerals in the National Museum of Natural History.

The Blue Heart may have begun its journey as a 102-carat stone, but its current size of 30.62 carats has made it an absolute stunner, proudly displaying a deep blue color, which may qualify as fancy intense blue or fancy vivid blue. The stone is a rare Type IIb diamond.

Blue diamonds are treasured greatly for their extreme rarity, so much so that individuals are willing to pay top dollar to have the opportunity to own one of these unique and rare items.  One of the most famous red diamonds, the Hancock Red, held the title for most expensive diamond ever sold per carat, for twenty years.  That record was broken by a blue diamond in 2007.  A 6.04-carat fancy vivid blue diamond that was auctioned at Sotheby’s in Hong Kong was sold for $7.98 million dollars, creating the new record of $1.32 million per carat. With colored diamonds becoming increasingly difficult to come by, we are developing a new appreciation for remarkable historic stones such as the Blue Heart.

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