The De Beers Group recently announced the launch in autumn 2018 of Lightbox, its synthetic diamond jewelry brand, at €800 for a one-carat stone: a bombshell that augurs some phenomenal upheavals. The De Beers Group, which spawned the slogan “A diamond is forever”, has been the leading producer of natural diamonds for decades. It will invest US$ 94 million over the next four years, this time endeavoring to convince the entire world that synthetic diamonds are the nec plus ultra. A hazardous balancing act.