Before the 1930s, diamonds were not the obvious symbol of love. They weren’t rare, they weren’t essential, and they definitely weren’t the go-to choice for engagement rings. Rubies, sapphires, and even turquoise were the romantic favorites. Diamonds were simply one option among many, sitting quietly in mines and vaults with no real emotional meaning attached to them.

All of that changed when De Beers made one of the boldest marketing moves in history. They realized they didn’t need to sell a gemstone. They needed to sell a feeling. If they could link diamonds to the idea of eternal love, they could create demand that had never existed before.

In 1947, their ad agency, N. W. Ayer, created the slogan that would transform the entire industry: “A Diamond Is Forever.” That simple line carried enormous weight. It suggested that love was not real unless a diamond represented it. It also had a strategic effect that many customers never realized. If diamonds were “forever,” people would be less likely to resell them. That kept the market tight, prices high, and demand constantly rising.

Then came another idea people still believe is tradition. The concept that a man should spend two months’ salary on an engagement ring. It was not customs or culture that created that expectation. It was De Beers deciding what love should cost and teaching the world to accept it.

Their strategy did not stop at North America or Europe. De Beers took their blueprint global. One of their biggest targets was Japan. In the 1960s, hardly any Japanese women wore engagement rings, and Western-style weddings were not common. Within twenty years, more than sixty percent of Japanese brides were wearing diamond rings. The shift was not cultural. It was engineered.

Behind the scenes, De Beers was not only shaping demand. They were controlling the supply. For decades, they held as much as ninety percent of the world’s diamond market. They managed distribution, pricing, and scarcity in ways that made diamonds feel rare, even though they were anything but.

Over the next few decades, De Beers continued to invent new emotional milestones to sell. The “Past, Present, and Future” ring positioned a three-stone design as the ultimate anniversary gift. The “Journey” collection used a sequence of increasingly larger diamonds to represent the growth of a relationship. In 2004, they launched the “Right-Hand Ring” campaign, encouraging women to buy diamonds for themselves as a symbol of independence and personal achievement.

With every campaign, De Beers wasn’t simply selling jewelry. They were selling stories, moments, and identities. They were redefining what love, success, and romance looked like.

Today, the impact is undeniable. More than a slogan, “A Diamond Is Forever” became the foundation for a tradition worth billions. De Beers managed to transform a common stone into the most powerful symbol of romance in modern culture.

They didn’t just shape the market. They shaped what the world believes love should look like.

‍