Can you tell the real thing from a fake? What if the difference no longer matters? The DeBeers diamond cartel cornered the market on eternal love with "A diamond is forever," but now a wave of undetectable synthetic diamonds has flooded global gem markets, threatening to expose the artifice that props up a multi-billion dollar industry. Interviewing diamond merchants, DeBeers executives, auctioneers, gemologists, designers, investigators and scientists, this film explores one of the most beautiful lies ever told.