An amorphous alumina formed by partial dehydration of gibbsite is characterized by observation and simulation of the central and satellite transitions of Al-27 magic angle spinning NMR spectra. The improved resolution of the AlO4, AlO5, and AlO6 sites in the (+/-3/2, +/-1/2) transitions allows the individual sideband manifolds to be simulated so that the NMR interaction parameters and the distribution of the quadrupolar interaction of each coordination can be deduced. Based on these parameters, simulation of the centerband provides the most accurate information to date on the distribution of aluminum between the three coordinations in an amorphous alumina.