> Probably but I doubt they'll be successful. For decades they've talked about the flawlessness and purity of diamonds, now faced with a superior product they have to change everyone's minds.

I believe that with really good marketing (which De Beers can easily afford) this should not be a problem. For example the fact that Persian rug makers traditionally include deliberate small imperfections into their carpets

> https://skeptics.stackexchange.com/questions/32361/did-persi...

might be a good starting point for how one might create such a campaign.