Princess Margaret’s Million Dollar Diamond Necklace

As the name of the jewel suggests, it originally belonged to Lady Mount Stephen, who was born Gian Tufnell. Gian was a courtier and a close friend of several members of the British royal family. Notably, she was described by the press as Queen Mary’s “most intimate friend.” As Miss Tufnell, she was often in the company of the Teck family, and in 1892, she was honorary secretary of the committee that raised funds to purchase the Girls of Great Britain & Ireland Tiara. In 1897, reportedly with the encouragement of the royal family, Gian became the second wife of the 1st Baron Mount Stephen, a Scottish-Canadian businessman who was one of the richest men of his era.

The second Lady Mount Stephen was more than thirty years younger than her husband, and she outlived him by more than a decade. Her friendship with Queen Mary endured until the very end. In the week before her death, Mary was a houseguest at Gian’s country estate, Brantridge Forest in Sussex. Gian’s obituary in the Telegraph notes that she was well enough on Friday, April 28, 1933, to go to the door of her house to bid farewell to Queen Mary on her departure. It therefore came as something of a shock when she passed away from a heart attack on Tuesday, May 2.

In her will, Lady Mount Stephen designated numerous items as bequests to members of the royal family. Princess Alice, Countess of Athlone, for example, received a diamond brooch set with part of the final spike driven to complete the Canadian Pacific Railway. Princess Louise, Princess Royal also received items, including a dessert service. But, naturally, it was Queen Mary who received the largest inheritance from her best friend.

Along with several royal portraits and an ivory bust of Queen Victoria, Gian left Mary a pair of diamond necklaces. The Belfast Telegraph, in their article about Gian’s estate, describes the two necklaces as “her diamond riviere of 34 stones” and “her diamond riviere of old Brazilian stones with a square diamond in the center.” The choice of these jewels as a legacy suggests that Gian really did know her friend very well. After all, Mary already had numerous diamond necklaces in her collection—the portrait above, taken around 1923, shows her wearing five of them!—and she liked to stack them up almost like a diamond-studded turtleneck in her later years. Two more would certainly help her in that quest.

Here’s a closer look at the first necklace described in that article, the “diamond riviere of 34 stones.” The diamonds in the piece are old-cut stones, set in the silver and gold necklace around 1900. The seven largest diamonds in the necklace measure between four and seven carats. The piece resides in a special fitted case of turquoise velvet bearing the logo of Tessiers Ltd., a London jewelry firm active under that name from 1920.

In this photograph, Queen Mary wears the necklace of 34 diamonds as part of an impressive stack of seven diamond rivières. The occasion was the coronation of her son, King George VI, in May 1937. Standing in front of her is a young Princess Margaret. Eventually, Mary either gifted or bequeathed the 34-diamond necklace to Margaret. Because of this chain of inheritance, you’ll sometimes see the necklace called “Queen Mary’s Diamond Rivière,” but more often, it’s simply called the “Lady Mount Stephen Necklace.”

Princess Margaret wore numerous diamond necklaces during her lifetime, but she appears to have personally owned only two of them. The Lady Mount Stephen is one of that pair. It can be notoriously difficult to differentiate between different diamond necklaces in photographs, but I believe that Margaret is wearing the necklace in this photo, taken en route to a gala event in the 1950s. (She’s also wearing the Cartier Halo Tiara.) You’ll note that the necklace rests neatly in the dip between Margaret’s collar bones.

The second diamond necklace that Margaret owned is this one, which has a tighter, more choker-like setting. It’s shorter than the Lady Mount Stephen Necklace, but just barely. There’s some debate about the provenance of this diamond necklace, it seems. Leslie Field writes that Margaret received “a rivière of diamond collets” as “a twenty-first birthday gift from her father.” In my opinion, that does appear to be this shorter necklace, which she wears in this photograph from August 1955.

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Margaret would later loan this second, shorter diamond necklace (which we’ll call the King George VI Diamond Necklace) on occasion to her daughter, Lady Sarah Chatto, who inherited it after Margaret’s death. Lady Sarah notably wore it for her own 21st birthday celebration (pictured above), which does suggest a possible confirmation of Field’s provenance. Much later, Sarah would wear it for a service of thanksgiving during the Diamond Jubilee in June 2012, stacked with a pearl and diamond necklace that also belonged to Margaret (via Queen Mary).

Princess Margaret sometimes wore both the King George VI Diamond Necklace and the Lady Mount Stephen Necklace stacked together, Queen Mary-style, to provide a little additional sparkle to a gala ensemble. This image comes from the Swedish state visit to London in the summer of 1954. Margaret wears the Cartier Halo Tiara (a loan from the Queen) and her Diamond Wheat-Ear Brooch (now in Lady Sarah’s jewelry box) with the necklaces. (She’s also piled on the decorations, wearing the sash of the Royal Victorian Order, the ribbon and badge of the Order of the Crown of India, and the Royal Family Orders of George V, George VI, and Elizabeth II.) The George VI Necklace is the shorter one, closer to Margaret’s chin, and the Lady Mount Stephen Necklace is positioned directly below it. You can see how close the two necklaces really are in length, and how easy it can be to confuse them in photographs!

So I’ll tell you that I’ve chosen the photographs in this article with relative confidence that I’m identifying the necklaces correctly, but there’s always the possibility that I’ve mistaken one for the other. For example, I’m almost certain that Margaret wore the Lady Mount Stephen Necklace at her sister’s coronation, paired again with the Cartier Halo Tiara and her Cartier Rose Brooch.

This glamorous photograph, taken in June 1953 shortly after the coronation, also shows Margaret wearing a diamond necklace, and I believe it’s the Lady Mount Stephen Necklace, given its length relative to Margaret’s collarbones.

This moody official portrait was taken by Cecil Beaton in August 1956 to celebrate Margaret’s birthday. She wears the Lady Mount Stephen Necklace here with her Ruby Girandole Earrings and a sparkling stack of bracelets.

Margaret wears the Lady Mount Stephen Necklace here in April 1958 for a dinner celebrating the 40th anniversary of the Royal Air Force, pairing it with the Cartier Halo Tiara and a pair of diamond brooches (one buckle-style, one floral).

On her wedding day in May 1960, Margaret paired the Lady Mount Stephen Necklace with the grand diadem she chose and purchased for herself: the Poltimore Tiara.

She often liked to pair the Poltimore with the Lady Mount Stephen Necklace, as well as a pair of classic diamond drop earrings. Here, she wears the combination in May 1977 for a gala at Covent Garden during the Queen’s Silver Jubilee celebrations.

And here, she wears the same combination of jewels almost two decades later for the State Opening of Parliament in October 1996. (The other “necklace” she’s wearing here is the Royal Victorian Chain.)

After Margaret’s death in 2002, her children made the decision to auction some of her jewelry to help cover the taxes on her estate. Of the two diamond necklaces in her jewelry box, they chose to sell the Lady Mount Stephen Necklace. (Lady Sarah, as I mentioned above, kept the George VI Necklace.) Here’s the Lady Mount Stephen Necklace on display at an open house at Christie’s in New York ahead of the sale in London. When the hammer fell on this necklace in June 2006, it had sold for a princely sum: £993,600, or more than $1.8 million USD (at the exchange rate at the time)—making it the most expensive jewelry item in the sale, even ahead of the mighty Poltimore Tiara.