Engagement Rings & Weddings / Celebrity
Grace Kelly Set the Trend For Emerald-Cut Diamond Engagement Rings
An icon of Old Hollywood glamour, Grace Kelly’s natural diamond engagement ring has a legacy all its own.
Published: October 3, 2025
Written by: Hannah Militano
A real-life fairytale, American actress Grace Kelly serendipitously fell in love with Prince Rainier III of Monaco, transcending from Hollywood royalty to real royalty as Princess Grace of Monaco. Receiving one of the most iconic celebrity engagement rings of all time, Prince Rainier III presented Grace Kelly with a Cartier diamond engagement ring. The magnificent ring featured a 10.48-carat emerald-cut diamond, flanked by a pair of tapered baguettes.
Kelly’s engagement ring has been credited with inspiring the famous emerald-cut diamonds of Elizabeth Taylor, Beyoncé, Amal Clooney, Anne Hathaway, Paris Hilton, and Sofia Richie, to name a few. It even had its own starring role in the 1956 film, High Society.
As legendary as it is, it wasn’t even the first ring presented to her by Prince Rainier. Before unveiling the now-iconic Cartier emerald-cut, he offered Grace Kelly a more modest eternity band. The switch to the dazzling 10.48-carat emerald-cut reflected not only Rainier’s devotion but also the Hollywood spectacle that surrounded their engagement.
Meet the Author
- Hannah Militano covers diamond jewelry trends, the fashion industry, pop culture, and celebrity news.
- She holds a Bachelor’s degree from the Fashion Institute of Technology.
- As a journalist, her work has been featured in publications such as Editorialist, Carine Roitfeld’s CR Fashion Book, L’Officiel USA, Grazia USA, Coveteur, and more.
Ahead, discover the fascinating tale of Grace Kelly’s engagement ring, a cinematic masterpiece that became one of the most influential rings in history.
A Fairytale Beginning: Grace Kelly’s First Engagement Ring
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 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.
Prince Rainier Upgraded Grace Kelly’s Engagement Ring to a Cartier Emerald-Cut Diamond
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.
Grace Kelly’s Engagement Ring Stole the Spotlight in High Society
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.
A Royal Wedding and a Legendary Cartier Connection
Shortly after wrapping up the film in Los Angeles, Kelly headed to Monaco to marry her prince. The couple tied the knot in a quiet civil ceremony at the palace before their lavish religious ceremony at Monaco’s Saint Nicholas Cathedral on April 19, 1956.
MGM, which had been Kelly’s studio, filmed the extravagant affair with a guest list filled with royals and Hollywood A-listers. The nuptials were watched by over 30 million viewers worldwide. The studio even gifted Kelly her ivory lace bridal gown, designed by Academy Award-winning costume designer Helen Rose, whom Kelly worked with on High Society.
Many credit Alfred Hitchcock with introducing Grace Kelly to Cartier while they were working on To Catch a Thief, in which she wore pieces from the jeweler’s Grain de Café collection. But her famous engagement ring truly cemented the relationship between the Hollywood star and the iconic jewelry House. 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.
Kelly was known to wear the jewel and her Cartier engagement ring up until her untimely death in 1982. At just 52, she 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.
Where Is Grace Kelly’s Engagement Ring Today?
After Grace Kelly’s death, both of her engagement rings were entrusted to the House of Grimaldi, the royal family of Monaco. Reports confirm that the Cartier emerald-cut diamond engagement ring and the eternity band remain in their collection today.
On occasion, the royal family has loaned the rings, along with other Cartier jewels from Grace Kelly’s archive, for special exhibitions. When Cartier unveiled its renovated Fifth Avenue flagship in 2016, the pieces were showcased for a month. Today, the boutique even features a dedicated room honoring Grace Kelly and her legendary jewels, ensuring that her iconic natural diamond engagement ring continues to inspire admirers around the world.
