Diamonds are produced in the bowels of the earth when carbon receives pressure and high temperatures. It has been used by humans as jewelry and mining as early as 2000 years before Christ, Until 1896, diamond mining only took place in India.
But scientists have managed to create man-made diamonds since 1954 with a temperature of 1400 °C and a pressure of 5 Gigapascals which is equivalent to 49346 atmospheric pressure (ATM).
Scientists from the Institute for Basic Science (IBS) and Ulsan National Institute of Science and Technology (UNIST) in South Korea have however succeeded in producing artificial diamonds at normal pressure. To produce it gallium metal, base, nickel and silicon are used. Then this metal mixture is exposed to hydrogen and methane gas at a temperature of 1,025 °C for 15 minutes in a chamber at a pressure of 1 ATM only.
Then the gas is emptied from the chamber and a diamond layer will be formed on the bottom. The resulting diamonds are not abundant or large in size. But this is sufficient for use in quantum computing for example. With lower pressure, these artificial diamonds can be produced at a lower cost.