Inside Grace Kelly’s Royal Jewelry Box: A Treasure Trove of Natural Diamonds
A real-life fairytale, Grace Kelly’s rise from Hollywood actress to the Princess of Monaco saw the star acquire some of the most exquisite diamonds imaginable.
Published: November 12, 2025
Written by: Hannah Militano
In the glittering orbit of Hollywood legends, Grace Kelly has a legacy all her own. A Hitchcock heroine who became an Academy Award-winning actress, Kelly transcended the Hollywood circuit when she married Prince Rainier III of Monaco in 1956, stepping into her royal role as Princess of Monaco.
Her influence on film, fashion, and culture endures, as does her enviable diamond jewelry. It’s been said that Prince Rainier III wished to adorn his bride-to-be with as many royal jewels as possible ahead of their wedding, showering the American actress in dazzling diamonds from legendary houses like Cartier and Van Cleef & Arpels.
Meet the Author
- Pierre Rainero is Cartier’s Image, Style, and Heritage Director, and has held the prestigious title for over two decades.
- Rainero has been tasked with preserving the legendary jeweler’s visual and artistic identity while ensuring its enduring relevance. He serves as a guardian of the brand, connecting Cartier’s revered history with its creative present.
At just 52 years old, the Princess of Monaco suffered a stroke while driving, which led to a fatal car accident—bringing a tragic end to the life of one of Hollywood and Monaco’s most enduring icons. Her jewels continue to live on—some remain within the royal family of Monaco, the House of Grimaldi, while others are preserved in the Palais Princier Collection. Many have been showcased in glittering exhibitions, and others are still worn by her daughters and granddaughters, carrying forward her luminous legacy
On November 12, Grace Kelly would have turned 96 years old. On her birthday, Only Natural Diamonds is looking back on some of Grace Kelly’s most regal diamonds.
Grace Kelly’s First Engagement Ring: The Ruby and Diamond Eternity Band
By the time Grace Kelly met her future husband, the actress had already secured her place as a prominent figure in Hollywood. Still in her early twenties, she had become a muse for Alfred Hitchcock’s celebrated films and had earned an Academy Award for Best Actress for her unforgettable performance in George Seaton’s The Country Girl.
That Oscar-winning role even played a part in facilitating her fairytale meet-cute with the Prince of Monaco. After her big win, Kelly attended the 1955 Cannes Film Festival to promote The Country Girl. While in the South of France, she attended a photoshoot at the Palace of Monaco, where she met her prince.
After she traveled back home, the pair continued to exchange love letters. By Christmas of that year, Prince Rainier traveled all the way to Philadelphia to propose to Kelly at her family home. He presented her with a natural diamond and ruby eternity band—its red and white gemstones symbolizing the colors of the Monaco flag. Widely believed to have been designed by Cartier and reportedly crafted from family heirlooms, the ring was modest but meaningful. Kelly debuted it publicly in January 1956, when she and Rainier formally announced their engagement to the press in Philadelphia.
Grace Kelly’s Iconic Emerald-Cut Diamond Engagement Ring
Only a month later, Prince Rainier replaced the understated eternity band with something more substantial, presenting Kelly with the 10.48-carat emerald-cut diamond from Cartier that we all know and love. Many believe the upgrade was made to reflect both Kelly’s stature as a Hollywood star and the grandeur expected of a future princess. To heighten the ring’s glamour, Cartier jewelers designed a platinum mount with baguette-cut diamonds on either side of the center stone.
At the time of their wedding in 1956, the engagement ring was priced at $4.06 million. Today, it’s estimated to be valued at $38.8 million, earning its place as one of the most expensive celebrity engagement rings ever.
In 1956, ahead of her wedding, Kelly filmed her final movie, High Society, before retiring from Hollywood to become a royal. Starring opposite Frank Sinatra and Bing Crosby in the musical remake of The Philadelphia Story, she shared the screen with another dazzling co-star—her new emerald-cut diamond engagement ring. Traditionally, a prop would have sufficed, but legend has it that when Prince Rainier learned the production planned to outfit her with a fake diamond, he swiftly upgraded her engagement ring so that Kelly could wear her own extraordinary natural diamond on camera.
Kelly starred as the wealthy socialite Tracy Samantha Lord, who is wedged between three men vying for her attention. Tracy is about to marry her fiancé, George (John Lund), when her ex-husband, Dexter (Bing Crosby), reappears and reveals he is still in love with her. To further complicate things, two newspaper reporters enter the fray, including Mike Conner (Frank Sinatra), who also becomes smitten with Tracy.
Even amid the drama, Kelly’s new sparkler commanded attention. In one witty exchange, Dexter glances at the diamond and quips, “That’s quite a rock, Sam,” before slyly turning to George with, “Some stone, George. Did you mine it yourself?
In another memorable scene, Kelly is seen lying on her bed, polishing the 10.48-carat diamond with the corner of a silk sheet before leaning back to admire it on her finger.
Cartier’s Image, Style, and Heritage Director, Pierre Rainero, tells Only Natural Diamonds, “A privileged relationship exists between Cartier and the princely family since their first purchases at the very beginning of the 20th century.”
He says, “These ties were consolidated by a first official supplier warrant granted in 1920 by Prince Albert I. It has been constantly renewed up to the present day. Therefore, Cartier provided several jewelry pieces for the marriage of Rainier III and Grace Kelly, starting with the engagement ring. Crafted in 1956, it is made of a platinum band and features an impressive 10.48-carat emerald-cut diamond framed by two baguette-cut diamonds, in an arrangement emblematic of Cartier. Unwilling to remove the ring, Grace Kelly wore it in her last film, High Society, giving it a full-fledged role.”
Grace Kelly’s Van Cleef & Arpels Diamond and Sapphire Daisy Brooch From Prince Rainier III
It’s been said that Prince Rainier III wished to give Grace Kelly as many Royal Jewels as he possibly could ahead of their royal nuptials. And on April 16, 1956, he contributed to his cause. With her love for flowers in mind, the Prince presented his bride-to-be with a Van Cleef & Arpels brooch, comprised of sapphire clusters, representing the flower’s disc florets, surrounded by billowing petals of natural diamonds to form the daisy, just days before their wedding.
According to the Royal Watcher, the stones reportedly date back to the 18th century and originally belonged to Princess Maria Caterina Brignole, the wife of Prince Honoré III of Monaco. Grace Kelly was known to wear the sentimental brooch on numerous occasions, like the reception at the Quirinale Palace in Rome during the couple’s State Visit to Italy in 1959, a visit to Canada in 1967, the Cannes Film Festival in 1975, and many portraits throughout the 1960s and 70s.
After her death in 1982, the Van Cleef & Arpels Sapphire Daisy Brooch was included in the Palais Princier Collection and has been exhibited among some of her other jewels in exhibits like ‘Grace Kelly: From Movie Star to Princess’ Exhibition at TIFF Bell Lightbox in Toronto in 2011.
Grace Kelly’s Cartier Diamond Festoon Necklace: A Royal Heirloom for Generations
The night of her civil ceremony, Kelly wore one of her wedding gifts to a celebratory gala – a Cartier diamond festoon necklace, including 64 brilliant and baguette-cut diamonds set in platinum. With three rows of glistening natural diamonds, the necklace was a staple in Kelly’s event wardrobe and royal photos. Kelly was known to wear the jewel until her untimely death in 1982.
Years later, her daughter Princess Caroline wore the Festoon necklace to Monaco’s National Day celebration in 2006. Six years later, the necklace went on display at the “El Arte de Cartier” exhibition at the Thyssen Bornemisza Museum in Madrid in 2012.
Then, Princess Caroline’s daughter, Charlotte Casiraghi, married film producer Dimitri Rassam in 2019, wearing her grandmother’s Cartier diamond Festoon necklace as a sweet family homage.
Grace Kelly and the Transformable Bains de Mer Tiara
After their civil ceremony earlier that day, Grace Kelly and Prince Rainier III stepped out for a celebratory gala at the Royal Opera House on April 18th, 1956– the day before their lavish religious wedding ceremony. That evening, Kelly was seen wearing the Cartier Bains de Mer tiara, gifted to her by the Société des Bains de Mer on behalf of her new subjects. The modern ruby and diamond diadem could be worn in a myriad of configurations.
The piece includes three scalloped ornaments set with natural diamonds and cabochon rubies set atop the tiara. They can also be worn separately, as brooches, hair ornaments, or even pendants attached to a necklace. Though she frequently wore it as a tiara, as she did during her State Visit to the Vatican in 1959 – Kelly also took full advantage of the jewel’s transformational capabilities.
Kelly wore the diamond and ruby ornaments as brooches, she wore them in her hair, and she even wore them on a necklace during the opening week of the original Broadway production of Flower Drum Song in 1958.
Grace Kelly Wore the Van Cleef & Arpels Ruby Tiara To Represent the Colors of Monaco
Ever the picture of regality, Grace Kelly wore a dazzling diamond and ruby Van Cleef & Arpels parure to attend the legendary Battle of Versailles Fashion Show in France in 1973. Five American designers – Anne Klein, Bill Blass, Halston, Stephen Burrows, and Oscar de la Renta – competed against five French designers – Hubert de Givenchy, Pierre Cardin, Yves Saint Laurent, Emmanuel Ungaro, and Christian Dior’s then-creative director, Marc Bohan.
Matching her raspberry-colored cape, the Princess of Monaco wore the stunning diamond and ruby tiara in her golden, braided tresses, with the matching necklace and cluster earrings. Just like her alternating ruby and diamond eternity band from Prince Rainier III, the red and white gemstones in her Van Cleef & Arpels parure represent the principality’s red and white colors.
From Empress Joséphine to Grace Kelly: The Historic Coronation Tiara
For Napoleon’s coronation at Notre-Dame Cathedral in Paris on December 2, 1804, Joséphine wore a magnificent custom-made diamond tiara, said to be set with more than 1,040 diamonds. Considered one of her most treasured jewels, the piece was later inherited by her daughter, Queen Hortense, and remained within the French Crown Jewels until 1887, when the French Republic dispersed the collection and sold at least part of the tiara to the luxury jeweler Van Cleef & Arpels.
After acquiring the historic jewel, Van Cleef & Arpels refurbished the tiara and occasionally loaned it to modern royals. Its most famous appearance took place in May 1966, when Grace Kelly, Princess of Monaco, who wore the tiara for the opulent ‘Second Empire’ Ball. Hosted in Paris to celebrate the opulence and artistry of Napoleon III’s era, the ball revived the grandeur of 19th-century court life.
