when was the first man made diamond made
1954
Introduction
Records of attempted diamond synthesis date back to the turn of the twentieth century. Numerous scientists claimed to have successfully synthesized diamonds between 1879 and 1928, but none was confirmed. In the 1940s, systematic research began in the United States, Sweden and the Soviet Union to grow diamonds, which culminated in the first reproducible synthesis of diamond in 1954. 
1879 1954 1879
Synthetic diamond Synthetic diamond Synthetic diamond
History Introduction History
After the 1797 discovery that diamond was pure carbon, many attempts were made to convert various cheap forms of carbon into diamond. The earliest successes were reported by James Ballantyne Hannay in 1879  . In the 1940s, systematic research began in the United States, Sweden and the Soviet Union to grow diamonds, which culminated in the first reproducible synthesis of diamond in 1954 The earliest successes were reported by James Ballantyne Hannay in 1879 and by Ferdinand Frédéric Henri Moissan in 1893
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Synthetic diamond [SEP] Introduction
This early research of diamond synthesis in the U.S., Sweden and the Soviet Union yielded the discovery of the CVD diamond (chemical vapor deposition) and HPHT diamond (high-pressure high-temperature) processes. These two processes still dominate the production of synthetic diamond, but researchers have since discovered a third and fourth method of diamond synthesis. A third method, known as detonation synthesis, entered the diamond market in the late 1990s. In this process, the detonation of carbon-containing explosives creates nanometer-sized diamond grains. Scientists have also demonstrated a fourth method of diamond synthesis, treating graphite with high-power ultrasound, but this process currently has no commercial application.