Diamonds aren’t forever. They chip, shatter, burn and fade. But with the help of the U.S.’s oldest ad agency and a female copywriter, diamond sellers managed to convince a generation that the relatively common gem was a rite of passage, a status symbol, and an everlasting token of love.
By 1948, the ad agency decided that images of glittering gems were no longer enough. It needed a tagline. So Ayer turned to Mary Frances Gerety, a high school graduate who had been on the job four years. She was one of the agency’s few female copywriters, and that spring, she struggled to distill the symbolic meaning of the gemstone into a single sentence. As Tom Zoellner describes it in “The Heartless Stone,” his 2006 book exploring the global diamond empire, the words finally came to Gerety one night after working almost until dawn. She asked a higher power to send her a line, and before falling asleep, she scribbled a few ideas on a pad and left it on her nightstand. When she woke up and reread what she’d written, she knew she had it: “A Diamond is Forever.”