All about the marketing
Creating the monopoly was the first step. Before the 1940s most people were not obsessed with diamond purchases to legitimize a marriage. It was the time of the Great Depression. The De Beers cartel used a globally reaching advertising campaign to convince men that that their love for a woman, and self-worth, could be measured in the size of a diamond ring. The phrase “a diamond is forever” was coined. Betrothed celebrities and royalty were photographed with engagement rings to stress its life affirming importance. By the 1960s, sales of diamonds in the United States exceeded 55% of couples. The tactic worked in other countries too. In 1967, only 5% of Japanese brides were presented with diamond rings. In 1981, it was about 60%.
