|Howard Tracy Hall|
October 20, 1919|
|Died||July 25, 2008
|Known for||Inventor of the synthetic diamond|
Howard Tracy Hall (October 20, 1919 – July 25, 2008) was an American physical chemist, and the first person who grew a synthetic diamond according to a reproducible, verifiable and witnessed process, using a press of his own design.
Tracy Hall was born in Ogden, Utah in 1919. His full name was Howard Tracy Hall, but he often used the name H. Tracy Hall or, simply, Tracy Hall. He was a descendant of Utah pioneers who were devout Mormons. Tracy grew up on a farm in Marriott, Utah. When still in the fourth grade, he announced his intention to work for General Electric. He attended Weber College for two years, and married Ida-Rose Langford in 1941. He went to the University of Utah in Salt Lake City, where he received his B. S. degree in 1942 and an M. S. in the following year. For the next two years, he served as an ensign in the U. S. Navy. He returned to the University of Utah in 1946, where he was Henry Eyring's first graduate student. and was awarded his Ph. D. in physical chemistry in 1948. Two months later he realized his childhood dream by starting work at the General Electric Research Laboratory in Schenectady, New York. He joined a team focused on synthetic diamond making, code named "Project Superpressure" headed by an engineer, Anthony Nerad.
As with many important inventions, the circumstances surrounding Hall's synthesis is the object of some controversy. What is undoubted is that he produced synthetic diamond in a press of his own design on December 16, 1954 and that he and others could do it over and over in the following week and that success led to the creation of a major super materials industry. What is also undoubted is that Hall was one of a group of about a half dozen of researchers who had focused on the syntheses for almost four years. These years had seen a succession of failed experiments, an increasingly impatient management, and a complex blend of sharing and rivalries among the researchers.
Hall's success, in his telling of the story, came about because of his determination to go his own way with a radical redesign of the press, which employed a doughnut-shaped binding ring (the belt) which confined the sample chamber and two curved and tapered pistons which pressed on the sample chamber. He "bootlegged" the machining of the first hardened steel version of this press, which showed some promise, and eventually got management to approve the construction of it in the tougher, much more expensive Carboloy (tungsten carbide dispersed in cobalt, also known as Widia). However, his experiments were "relegated" (Hall claimed) to a smaller, antique, leaky 400 ton press, rather than a more expensive and new thousand ton press used by other members of the team.
The composition of the starting material in the sample chamber, catalyst for the reaction, and the required temperature and pressure were little more than guesses. Hall used iron sulfide and a form of powdered carbon as the starting material, with tantalum disks to conduct the electricity into the cell for heating it. The experiment was conducted at about 100,000 atmospheres, 1600 °C and took about 38 minutes. Upon breaking open the sample, clusters of diamond octahedral crystals were found on the tantalum metal disks, which apparently acted as a catalyst.
GE went on to make a fortune with Hall's invention. GE rewarded Hall with a $10 Savings Bond, in addition to his regular salary. 
Hall left GE in 1955 and became a full professor of chemistry and Director of Research at Brigham Young University. At BYU, he invented the tetrahedral and Cubic press systems. For many years, the first tetrahedral press was displayed in the Eyring Science center on campus at BYU. In the early 1960s Hall invented polycrystalline diamond (PCD). He founded Novatek and was a co founder of MegaDiamond, both of Provo Utah.
On Sunday, July 4, 1976, he became a bishop in the Church of Jesus Christ of Latter-day Saints and served five years. Later he served a church mission to southern Africa with his wife, Ida-Rose Langford. He died on July 25, 2008 in Provo, Utah, at the age of 88. He had seven children, 35 grandchildren and 53 great-grandchildren.
- In 1970 he was awarded the Chemical Pioneers Award by the American Institute of Chemists.
- In 1972 he was awarded the American Chemical Society Award for Creative Invention: "For being the first to discover a reproducible reaction system for making synthetic diamonds from graphite, and for the concept and design of a super high pressure apparatus which not only made the synthesis possible, but brought about a whole new era of high pressure research."
- In 1977 he was the recipient of the James C. McGroddy Prize for New Materials from the American Physical Society.
- The 1994 Governor's Medal for Science and Technology
He was granted 19 patents in his career. Some especially notable ones were:
- U.S. Patent 2,947,608 or  "Diamond Synthesis" Howard Tracy Hall, Aug. 2, 1960.
- U.S. Patent 2,947,610 or  "Method of Making Diamonds" Howard Tracy Hall, Herbert M. Strong and Robert H. Wentorf, Jr., Aug. 2, 1960.
- U.S. Patent 3,159,876 or  "High Pressure Press" Howard Tracy Hall, Dec. 8, 1964.
- "Tracy Hall, Leading Figure in Diamond Synthesis, Dies Aged 88". element six. Retrieved 2009-05-05.
- H. T. Hall (1960). "Ultra-high pressure apparatus". Rev. Sci. Instr. 31 (2): 125. Bibcode:1960RScI...31..125H. doi:10.1063/1.1716907.
- H. T. Hall (1958). "Ultrahigh-Pressure Research: At ultrahigh pressures new and sometimes unexpected chemical and physical events occur". Science 128 (3322): 445–9. Bibcode:1958Sci...128..445H. doi:10.1126/science.128.3322.445. PMID 17834381.
- R. M. Hazen (1999). The diamond makers. Cambridge University Press. pp. 113; 125. ISBN 0-521-65474-2.
- Maugh II, Thomas H. "General Electric chemist invented process for making diamonds in lab".