<P> In 1941, an agreement was made between the General Electric (GE), Norton and Carborundum companies to further develop diamond synthesis . They were able to heat carbon to about 3,000 ° C (5,430 ° F) under a pressure of 3.5 gigapascals (510,000 psi) for a few seconds . Soon thereafter, the Second World War interrupted the project . It was resumed in 1951 at the Schenectady Laboratories of GE, and a high - pressure diamond group was formed with Francis P. Bundy and H.M. Strong . Tracy Hall and others joined this project shortly thereafter . </P> <P> The Schenectady group improved on the anvils designed by Percy Bridgman, who received a Nobel Prize for his work in 1946 . Bundy and Strong made the first improvements, then more were made by Hall . The GE team used tungsten carbide anvils within a hydraulic press to squeeze the carbonaceous sample held in a catlinite container, the finished grit being squeezed out of the container into a gasket . The team recorded diamond synthesis on one occasion, but the experiment could not be reproduced because of uncertain synthesis conditions, and the diamond was later shown to have been a natural diamond used as a seed . </P> <P> Hall achieved the first commercially successful synthesis of diamond on December 16, 1954, and this was announced on February 15, 1955 . His breakthrough was using a "belt" press, which was capable of producing pressures above 10 GPa (1,500,000 psi) and temperatures above 2,000 ° C (3,630 ° F). The press used a pyrophyllite container in which graphite was dissolved within molten nickel, cobalt or iron . Those metals acted as a "solvent - catalyst", which both dissolved carbon and accelerated its conversion into diamond . The largest diamond he produced was 0.15 mm (0.0059 in) across; it was too small and visually imperfect for jewelry, but usable in industrial abrasives . Hall's co-workers were able to replicate his work, and the discovery was published in the major journal Nature . He was the first person to grow a synthetic diamond with a reproducible, verifiable and well - documented process . He left GE in 1955, and three years later developed a new apparatus for the synthesis of diamond--a tetrahedral press with four anvils--to avoid violating a U.S. Department of Commerce secrecy order on the GE patent applications . Hall received the American Chemical Society Award for Creative Invention for his work in diamond synthesis . </P> <P> An independent diamond synthesis was achieved on February 16, 1953 in Stockholm by the ASEA (Allmänna Svenska Elektriska Aktiebolaget), one of Sweden's major electrical manufacturing companies . Starting in 1949, ASEA employed a team of five scientists and engineers as part of a top - secret diamond - making project code - named QUINTUS . The team used a bulky split - sphere apparatus designed by Baltzar von Platen and Anders Kämpe . Pressure was maintained within the device at an estimated 8.4 GPa for an hour . A few small diamonds were produced, but not of gem quality or size . The work was not reported until the 1980s . During the 1980s, a new competitor emerged in Korea, a company named Iljin Diamond; it was followed by hundreds of Chinese enterprises . Iljin Diamond allegedly accomplished diamond synthesis in 1988 by misappropriating trade secrets from GE via a Korean former GE employee . </P>

How much psi does it take to make a diamond
find me the text answering this question