In a Valentine’s Day commentary on ABC’s 20/20, John Stossel challenged the idea that “diamonds equal love.”

“Why do couples everywhere who wish to declare their love go out and pay big bucks for diamonds?” he asked. “Since 1940, De Beers’ brilliant ad campaign has been convincing Americans that diamonds mean love. … Years of listening to this propaganda has convinced us that giving diamonds is an age-old tradition. This is just a sales pitch. In the 1930s, when my parents were married, it wasn’t customary for men to give women diamond rings.”

Stossel also challenged the notion that diamonds are really rare. “If De Beers hadn’t controlled the world market for decades, diamonds would be much cheaper,” he said.

In perhaps the most damaging segment, Stossel showed passers-by at Grand Central Station a cubic zirconia and a $10,000 diamond and asked which they liked more.

“Most people could not tell the difference,” he says. “Of dozens of people we asked, nearly half picked the cubic zirconia. Yet women told us [that] even if they had preferred the look of the imitation, they’d still rather be given the diamond. ‘It just makes you feel like you’re special,’ said one woman. ‘I know what I want on my finger, and it has to be the real thing.’ “

Stossel concluded: “We’ll spend more for a rock because a South African cartel has run a great ad campaign? Apparently we will. Give me a break!”