Quartz single-crystal samples consisting of alpha-quartz crystal structure were neutron irradiated to fluences of x 10(18), 4 x 10(19), and 2 x 10(20) n/cm(2) (E > 0.1 MeV) at two temperatures (52 and 95 degrees C). The changes in the alpha-quartz phase as a function of these two conditions (temperature and fluence) were studied using x-ray powder diffraction (xRD), Raman spectroscopy, and transmission electron microscopy (TEM), and the results acquired using these complementary techniques are presented in a single place for the first time. xRD studies showed that the lattice parameters of alpha-quartz increased with increasing neutron flux. The lattice growth was larger for the samples that were neutron irradiated at 52 degrees C than at 95 degrees C. Moreover, an amorphous content was determined in the quartz samples neutron irradiated at 4 x 10(19) n/cm(2), with the greater amount being in the 52 C irradiated sample. Complete amorphization of quartz was observed at a fluence of 2 x 10(20) n/cm(2) (E > 0.1 MeV) using xRD and confirmed by TEM characterization and Raman spectroscopic studies. The cause for alpha-quartz lattice expansion and sample amorphization was also explored using xRD and Raman spectroscopic studies.