Now you can make diamonds in a microwave by Victor Luckerson @FortuneMagazine August 27, 2015, 2:58 PM EDT E-mail Tweet Facebook Linkedin Share icons Diamonds really are forever, now that we can manufacture them. There’s a growing market for man-made jewels grown in science labs, Bloomberg reports. The diamonds are made by placing a carbon seed in a microwave chamber and superheating the substance into a plasma ball, which crystallizes into the much-desired jewels. Experts can only tell the difference between the manufactured diamonds and traditionally mined ones using a machine. The man-made diamonds are starting to be sold by retailers such as Wal-Mart WMT , although they still make up just a small fraction of total diamond sales. In 2014, an estimated 360,000 carats of lab-grown diamonds were manufactured while about 146 million carats of natural gems were mined. The number of man-made diamonds is expected to reach 20 million carats by 2026. (One carat = 0.2 grams). Diamond industry heavyweights such as De Beers say they have nothing to fear from startups pushing lab-produced gems. The company told Bloomberg that the “formation,” “history,” and “emotional significance” of mined diamonds make them unique.