A Brief History (8.02)
Synthetic diamonds go back to the 1950s in the U.S. and Sweden. Their use was strictly industrial -- hence not a threat to the jewelry industry. In 1970, General Electric came up with a gem-quality synthetic diamond, but the cost of producing it was far greater than its natural counterpart value.
De Beers and General Electric have come up with further improvements along with Sumitomo of Japan and several Russian facilities of the former Soviet Union since the ‘70s.