De Beers 'The Promise' Small 18 Carat Rose Gold Diamond Engagement Ring

De Beers is among the world’s largest diamond suppliers by volume. Nearly one hundred percent of the company’s revenue comes from mining and producing diamonds, and today, De Beers engagement rings, wedding rings, tennis bracelets and other pieces are widely admired by jewelry wearers near and far.

De Beers Mining Company was established as such in the 1880s by British businessman Cecil Rhodes. Initially, Rhodes provided water pumping systems to miners in South Africa before he began to purchase mines (by 1888, De Beers Mining Company owned nearly every mine in South Africa). Eventually, De Beers operated distribution and production of diamonds on a massive scale. 

German-born industrialist Ernest Oppenheimer — founder of the Anglo American Corporation and a rival of De Beers in the diamond game — began to buy shares of Rhodes’s company as they became available in the early 20th century. Oppenheimer was owner and chairman of De Beers by the late 1920s.

De Beers has played a significant role in all parts of the diamond world over the years. In 1940, for example, the company partnered with the Gemological Institute of America to market the 4Cs. This system — the 4Cs being color, clarity, cut and carat weight — was established by former jeweler and founder of the GIA, Robert M. Shipley, and lays out the guidelines that determine how diamonds are graded. A lecturer with the Philadelphia, Pennsylvania-based advertising agency that worked with De Beers, N.W. Ayer & Son, traveled around the United States during the early 1940s to share guidance with jewelers on the 4Cs and on how to talk about diamonds with their clientele. The agency would play even a larger role in promoting diamonds in the years that followed.

Postwar engagement rings were intended to be simpler than those that preceded them — after the war, platinum was no longer reserved for military use and the precious stones in engagement rings were larger. In 1947, with the support of N.W. Ayer & Son, De Beers introduced the slogan “A diamond is forever” in a marketing campaign that emphasized a connection between diamonds and romance. This sparkling copy was penned by the agency’s copywriter Frances Gerety. 

Newer engagement rings were designed with a focus on the beauty of the diamond, and the sale of diamonds soared. Diamond engagement rings became intertwined with the post–World War II marriage boom, which coincided with the ascension of specific diamond cuts.

Throughout the 1950s, ‘60s and ‘70s, De Beers expanded operations across the globe. In 1986 in a South African mine, the company unearthed the Centenary Diamond. One of the most famous diamonds in the world, the heart-shaped Centenary Diamond weighs 273 carats. It was unveiled in 1988 for the 100th anniversary of De Beers. Since the 1990s, rumors have swirled that De Beers sold the stone to a private buyer; the company will neither confirm nor deny the claim, citing client confidentiality.

In the early 2000s, De Beers opened stores in London, New York City, Hong Kong and elsewhere. The company is today leading an effort to prioritize philanthropic efforts as well as transparency in diamond origins. 

On 1stDibs, find vintage De Beers rings, bracelets, necklaces and more.