Synthetic gem-quality diamonds are old news by now. Since the 2010s, you have been able to make essentially flawless diamonds by vacuum deposition, of higher quality than anything found in nature, weighing up to a hundred karats or so.

They’re also vastly more ethically produced than most natural diamonds, and don’t have prices inflated by the artificial scarcity imposed by the De Beers monopoly.

https://en.wikipedia.org/wiki/Synthetic_diamond

Monopoly? DeBeers itself is virtually worthless now, its parent Anglo American can’t even sell it at a huge discount.

https://www.forbes.com/sites/timtreadgold/2026/02/22/diamond...