Ironically, De Beers. They've promised a line of lab-grown diamonds this year at $800 for 1 carat, which is the lowest price I've seen. The line is starting wit

Ironically, De Beers. They've promised a line of lab-grown diamonds this year at $800 for 1 carat, which is the lowest price I've seen. The line is starting with pink, blue, and white. Colorless is still a pain, though - apparently 1 carat gem-quality colorless is still about $4,300 at market rates.