Semi-related, but here's an interesting fact, De Beers (the company that popularised diamonds for engagement rings, hoards a huge supply, and creates artificial scarcity) has also invested heavily in lab grown diamonds: https://www.bloomberg.com/news/articles/2018-05-29/de-beers-...

They've been doing this to try and undercut lab diamond growing company's in an attempt to retain control of the diamond market in an era where lab diamonds are becoming more and more popular as people consider their ethical choices.