Ever since man took an interest in diamond mining, the diamond industry has been treated to some of the most exquisite and unique gemstones. Most of these diamonds derive their uniqueness from their sheer gigantic size.
Others are considered special in the way they sparkle while some have earned their fame due to the publicity they generated during their mining and cutting operations. One such diamond that has been a household name in the jewelry industry is the Blue Heart Diamond.
The Blue Heart Diamond Quick Facts
Origin: Premier Mines, South Africa
Initial weight: 100.5 carats
Weight after processing: 30.62ct
Color: Light grey-blue
Clarity Grade: VS-2
Creator: Atanik Eknayan, Harry Winston, Inc.
Date Created: 1909/1964
Origin, History and Etymology
The Blue Heart Diamond was discovered at Premier Mines in South Africa, in 1908. At some point, there was controversy surrounding the real origin, with some people arguing the diamond might have come from India. The Blue Heart Diamond weighed a whopping 100.5 carats at the time of its discovery. Subsequent cutting and polishing activities would later reduce that weight to 30.62 carats. Like many similar gigantic diamond finds, the Blue Heart Diamond began to generate media attention as soon as it was discovered.
In 1909, the Premier Transvaal Diamond Mining Company purchased the diamond, and a year later, the cutting and processing work began. The cutting work was entrusted to a Paris-based French jeweler known as Atanik Eknayan. Mr Eknayan carefully cut and faceted the diamond into the heart-shaped stone we know of it today. In the same year, the Blue Heart Diamond was set as the center stone of a lily-of-the-valley ornament necklace. A year later, the French jeweler, Pierre Cartier purchased the gemstone and sold it to the Unzue family of Argentina. Maria Unzue gifted the diamond to her niece, Angela Gonzalez Alzaga, as a wedding present in 1936.
In 1953, Van Cleef & Arpels acquired the Blue Heart Diamond and reset it into a pendant. The elegant pendant also featured other unique gems, including a 2.05-carat pink diamond, making it one of the most beautiful necklaces of the time. Later that year, the $300,000 necklace would be sold to a Swiss industrialist known as Baron Hans Heinrich Thyssen-Bornemisza.
After that, the diamond changed many hands, mostly falling under the ownership of reputable jewelry dealers. Harry Winston acquired the gem in 1959 from Nina Dyer, who was an ex-wife to Mr Thyssen-Bornemisza. Harry Winston then mounted the diamond on a ring before selling it to Marjorie Merriweather Post, the American socialite who founded General Foods Inc., in 1960. Mrs Post was the last private owner ever to have handled the Blue Heart Diamond. She eventually gifted the gemstone to the Smithsonian Institution in Washington D.C., in 1964. And that’s where the diamond has remained to date.
In 1997, the Gemological Institute of America graded the stone as a Natural Fancy Blue Color Diamond. After the grading process, the diamond was assigned a clarity grade of VS2 (very slightly included), making it one of the world’s largest flawless diamonds.
The name “Blue Heart” was inspired by both the diamond’s rare deep-blue color and its heart-shaped cut. It’s arguably one of the world’s prettiest blue diamonds and coupled with its heart-shaped cut. It’s also one of the rarest. The Blue Heart Diamond is often referred to as Unzue. Ostensibly, in tribute to Mrs Unzue, the Argentinean woman who owned the diamond for a staggering 43 years after purchasing it from Pierre Cartier, just two years after its discovery.
Blue Heart is also often referred to as "Eugenie Blue’’. It’s rather unclear why the diamond is named after the French Empress Eugenie whose reign ended long before the diamond was discovered. The only French link to the diamond is the fact that it was cut and faceted by Atanik Ekyanan.
In terms of size, the Blue Heart Diamond is believed to be two-thirds the size of another significant diamond find, the Hope Diamond.
Characteristics of the Blue Heart Diamond
When Harry Winston acquired the Blue Heart Diamond, they mounted the stone in its present platinum ring setting. The choice of the ring setting was convenient, as it added more brilliance to the already quite sparkly stone. Winston reckoned that a platinum ring would accentuate the deep blue color of the diamond, thereby enhancing its fire and brilliance. The diamond’s blue color is attributed to the trace amounts of boron within the stone’s crystal structure, replacing several carbon atoms.
The Blue Heart Diamond isn’t the only gemstone at the National Gem Collection. The collection also houses some of the world’s popular gems, such as the Hope Diamond. However, the Blue Heart is outstanding due to its lively blue color and the fancy heart shape.
The Blue Heart Diamond enjoys the coveted distinction as the world’s largest heart-shaped blue diamond. The gemstone has held that position since it was cut and faceted in 1909. And considering how difficult it is to come by large blue diamonds, this gemstone might hold on to that title for much longer. The intricate process involved in the cutting and faceting of heart-shaped diamonds means there’s only a handful of diamonds with such attributes. And that adds an extra layer of rarity and uniqueness to the Blue Heart.
In fact, there are only three other famous large, heart-shaped blue diamonds in the world. The first one is the Heart of Eternity weighing 27.64-carats, which was exhibited at the London’s Millennium Dome in 2,000. Next is the iconic 203.04-carat Millennium Star. And lastly, the 5.46-carat heart-shaped Marie Antoinette diamond. Blue Heart ranks as the world’s 11 th largest diamond overall.
Additionally, the Blue Heart Diamond has earned itself a place among the Type IIb group of diamonds. The Type IIb category of diamonds includes only the naturally-colored blue diamonds. It’s important to note that the occurrence of naturally-colored blue diamonds is less than 0.1% of all the other natural diamonds. That makes them the rarest and some of the most expensive stones out there. Diamonds that fall under the Type IIb category either contain no nitrogen at all, or the level of nitrogen in their crystals cannot be detected even by the most sophisticated gemological equipment.
The Type IIb category of diamonds is contrasted from the Type IIa category due to the fact that diamonds in the latter category are not only free of nitrogen but also other chemical impurities. About 1 – 2% of the world’s naturally-occurring diamonds belong in the Type IIa category. Unfortunately, Type IIb diamonds, of which Blue Heart belongs, contain traces of impurities, mostly boron. As we already pointed out, it’s actually the boron element in the Blue Heart’s crystal structure that accounts for the diamond’s deep blue color. That’s because boron changes the diamond’s light absorption spectrum significantly. Besides, the presence of boron in the Blue Heart Diamond also makes the gemstone a semiconductor of electricity.
Fun Facts about the Blue Heart Diamond
Origin Shrouded in Mystery
At some point, doubts were expressed with regards to the exact origin of the Blue Heart Diamond. Some people believed that the diamond might have originated in India. That’s because, around the time the gemstone was supposedly discovered, India was a major world producer of rough diamonds.
However, these doubts have since been cleared by researchers at the National Museum of Natural History. The researchers argued that by the dawn of the 20 th century, most mining activities in India had ceased. In fact, operations had already been abandoned in India’s most diamond-productive region of Eastern Deccan Plateau.
To demystify the India origin theory, researchers at the Natural History Museum dug into the archives of De Beers where they unearthed evidence suggesting the Blue Heart was actually discovered at Premier Mines in South Africa. Besides uncovering the origin, the researchers also established that the diamond was discovered in November 1908 and initially weighed 100.5 carats.
The Blue Heart Diamond is one of the gemstones that fell under the ownership of many entities before finding its permanent home at the National Gem Collection. Though its history began in South Africa, Blue Heart would traverse the world, falling under the ownership of both private entities and jewelry companies.
The most notable private entities to have owned the diamond include the Unzue family, Hans Heinrich Thyssen-Bornemisza family and Marjorie Merriweather Post. Some prominent jewelers that once acquired the Blue Heart include Harry Winston and Pierre Cartier. However, it’s the Unzue family that owned the diamond the longest - a record of 43 years. No wonder the gemstone is oftentimes referred to as Unzue Diamond.
The histories of the world’s most iconic diamonds usually assume a similar trajectory. First, the diamond is discovered, then it’s popularized and finally sold to a royal ruler or auctioned to private jewelers. The Blue Heart Diamond has witnessed somewhat similar circumstances.
But despite its rarity, the final owner of the diamond, Mrs Post, appears not to have attached so much economic importance to the diamond. She eventually donated the stone to the National Museum of Natural History of the Smithsonian Institution based in Washington DC. The diamond is presently on display in the Janet-Annenberg Hooker Hall of Geology, Gems & Minerals.
The Blue Heart Diamond remains one of the world’s most cherished gems. And though it isn’t the world’s largest diamond ever discovered, it’s the rarest in terms of its color and shape. That explains why the Smithsonian Institution is keen on retaining the diamond as part of its vast collection of precious and unique gemstones.