A new ultra-hard form of carbon may exist between graphite and diamond.The structure of the new form of carbon resembles that of both graphite and diamond.Punchstock Carbon can exist in a form halfway between graphite and diamond, say researchers in China and the United States. And they believe this stuff is as hard as diamond itself.Yanming Ma of Jilin University in Changchun, China, and his colleagues think that the new carbon material they have predicted in theoretical calculations1 may have been made already, in 2003.At that time, Ho-kwang Mao of the Carnegie Institution of Washington in Washington DC, a co-author...