Lab grown diamonds are cheaper, completely ethically created, and can be made to a higher level of purity and quality than naturally occurring diamonds, since they are created under highly specific laboratory conditions.
Seriously: terrestrial diamond mining should be made illegal, now that we can make industrial and jewelry diamonds (as well as many other gemstones) at a higher average quality and far lower cost than those found in nature. But it won’t be, because a few people with far too much money invested in Diamond mining won’t let it happen, and they’re not afraid of orchestrating a coup or three if they think it’ll get them what they want.