How do they do artificial diamonds?

I read an article recently about the possibility of using diamond as a building material. As I watch this video, though and see the massive amount of effort that goes into creating even these relatively tiny diamonds, I'm thinking that we're still a ways off from making any sorts of floors or windows from this carbon allotrope anytime soon.

I love the use of concentrated hydrochloric acid to get rid of the metal slug around the final - and hopeful - diamond.