As with many important inventions, the circumstances surrounding Hall's synthesis is the object of some controversy. It is undoubted that he produced synthetic diamond in a press of his own design on December 16, 1954 and that he and others could repeat the process following Hall's procedure, a success which led to the creation of a major supermaterials industry. What is also undoubted is that Hall was one of a group of about a half dozen researchers who had focused on achieving the synthesis 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.