Marjorie Merriweather Post: 'My Blue Diamond Is Prettier Than That Other One'

In honor of April's official birthstone, we present the fascinating backstory of the historic and well-traveled "Blue Heart Diamond," a 30.62-carat stunner that Smithsonian benefactor Marjorie Merriweather Post described as "prettier than that other one" while escorting guests on a tour of the National Gem Gallery. The object of her snub was the "Hope Diamond."

The origin story of the Blue Heart Diamond can be traced back to October of 1909, when an exceptional 100.5-carat deep blue diamond was unearthed at De Beers' Premier Mine in South Africa. Two months later, the crystal was sold for £3,979 (equivalent of £600,000 or $775,000 today) to a French diamond cutter named Atanik Eknayan.

Eknayan faceted the gem into a 30.62-carat heart-shaped brilliant and sold it in 1910 to famed Fifth Avenue jeweler Pierre Cartier. Cartier placed the impressive stone as the center of a luxurious lily-of-the-valley corsage that included smaller pink and blue diamonds.

In 1911, the corsage caught the eye of the Argentinian heiress and philanthropist Maria Unzué de Alvear, who owned it for the next 25 years.

In 1936, at the age of 74, she presented the piece as a wedding gift to her niece, Angela Gonzales Alzaga. In his book, Unearthed, former Smithsonian National Gem Collection curator Dr. Jeffrey Post noted that the Blue Heart Diamond is sometimes referred to as the "Unzué Heart" due to its close ties to that family.

The Blue Heart Diamond was reset as a pendant after it was acquired by Van Cleef & Arpels in 1953. A member of the Unzué family told Post that the price exceeded that of a very fine house in Buenos Aires at the time.

That pendant, which featured the 30.62-carat Blue Heart Diamond dangling below a 2.05-carat pink diamond and 3.81-carat blue diamond, was sold in 1953 to Swiss industrialist Baron Hans Heinrich Thyssen-Bornemisza. The Baron gifted the pendant to fashion model Nina Sheila Dyer, who he would marry in 1954.

The marriage lasted only 10 months, but Dyer possessed the Blue Heart Diamond until she sold it to New York City luxury jeweler Harry Winston in 1959. Winston reset the stone into a ring and surrounded it with 25 round brilliant, colorless diamonds.

In 1964, Winston sold the ring to Marjorie Merriweather Post, the heiress to the Post cereal fortune and an avid collector of high-profile fine jewelry. As Jeffrey Post tells the story, only two months after the purchase, "Marjorie Merriweather Post arrived at the office of Smithsonian secretary Leonard Carmichael bearing gifts, her bag brimming with jewelry that she was gifting to the Smithsonian Institution."

One of those pieces was the Blue Heart Diamond. Interestingly, her donation included one stipulation: That she be able to borrow the jewelry at her discretion, which she did in 1964, 1968 and 1970.

Although the Blue Heart Diamond is only two-thirds the weight of the far more famous 45.52-carat Hope Diamond, jewelry aficionados generally agree that the Blue Heart Diamond displays a more lively blue color.

Ms. Post clearly agreed.

As Jeffrey Post explains, "Once, when walking through the museum's Gem Gallery, Ms. Post was overheard saying to her guests that 'my blue diamond is prettier than that other one.'"

Marjorie Merriweather Post's donation of the Blue Heart Diamond was one of many notable pieces gifted to the Smithsonian by the Post family. Others included the “Maximilian Emerald Ring,” “Napoleon Diamond Necklace,” “Marie-Louise Diadem” and the “Post Emerald Necklace.” Marjorie Merriweather Post passed away in 1973 at the age of 86.

Credit: Image by Chip Clark, courtesy of the Smithsonian.