 The discovery had no practical importance, but surprised most scientists as superconductivity had not been observed in covalent semiconductors, including diamond and silicon.The priority of many discoveries in science is vigorously disputed (see, e.g., Nobel Prize controversies).Another example, after Sumio Iijima has "discovered" carbon nanotubes in 1991, many scientists have pointed out that carbon nanofibers were actually observed decades earlier.