|Brown, Lemay & Burstein. Chemistry: The Central Science. 7th ed. Upper Saddle River NJ: Prentice Hall, 1997.||"At very high temperature and pressure (on the order of 100,000 atm at 3000 degrees celsius) graphite converts to diamond.||100,000 atm|
|The New Encyclopedia Britannica. vol. 2. Chicago: Encyclopedia Britannica, 1998.||"The stones were made by subjecting graphite to pressures approaching 7 gigapascals (1 million lbs per sq in) and to temperatures above 1700 degrees celsius in the presence of a metal catalyst."||68,000 atm|
|Diamonds … Pressure … and Peanut Butter. Tyler-Adam Corp. New York, New York.||"It will only work if you can sustain a temperature level of 1000 degrees centigrade while keeping up the pressure of over fifty thousand atmospheres"||50,000 atm|
|"A Diamond Made To Flow Like Plastic, In Lab Test." New York Times. 28 March 1978.||"The force compressing two small diamonds was 25.2 million lbs per sq in which is equal to 700 times the pressure exerted on Earth's crust by Mt. Everest."||1,700,000 atm|
|Formation Conditions: Heat and Pressure. The Nature of Diamonds. American Museum of Natural History.||"13,000 atm-88,000 atm, 0 K-3000 K"[graph]||13,000–88,000 atm|
|"Physics Update." Physics Today. 50, 12 (December 1997): 9.||"… using very high pressure (above 10 GPa) and temperature (typically above 1600 K)"||99,000 atm|
A diamond is a clear hard solid formed by a covalent network of carbon atoms. Artificial diamonds are made by subjecting graphite (one of the three crystalline forms of carbon) to very high temperatures and pressures. Most of pure diamond's fundamental properties are retained in artificial diamonds. For example, artificial diamonds have extreme hardness, broad transparency, high thermal conductivity and high electrical resistivity. Artificial diamond making is a very expensive process. Therefore most are produced as small crystals that are used to provide hard coatings for industrial equipment such as grinding wheels, machine tools, wire drawing dies, quarrying saws and mining drills.
Artificial diamonds have been researched since the early 1950s. The first man involved was American physicist Percy Williams Bridgman. His research included extensive studies of materials subjected to high pressure. He won a Nobel prize in physics for his achievements but never actually created synthetic diamonds. Unfortunately, for Lundblad, it was never announced. However, on December 8, 1954, a scientist from General Electric subjected black carbon powder to pressures of 50,000 atmosphere for 16 hours and made two small synthetic diamonds.
The pressure used to create artificial diamonds varies with temperature. Therefore, there is no single number for the pressure required to produce an artificial diamond.
Ilene Weintraub -- 1998
External links to this page:
- Naturoids: on the nature of the artificial, Massimo Negrotti