I'm highly curious about the economics around manufacturing diamonds, and what effects it'll have on the diamond markets, if any:

Manufactured Gem Grade Diamonds

I saw manufactured diamond about 16 years ago, but it wasn't gem grade. The folks that had it were experimenting with how to use it to cool enterprise level computing hardware. Their favorite demonstration was to have someone touch the diamond bar to ice, and you could feel the cold of the ice instantly at the end of the bar (about 5" long). Just a couple years ago they launched a consortium to develop the technology: NanoWerk

With billionaire investment power, I suspect we'll see more about this.