High alumina radioactive waste calcine is produced at the Idaho Chemical Processing Plant (ICPP) by feeding a taw liquid waste stream through a fluidized bed calcitter. Further solidification of this calcine via chemical bonding necessitates determination of the amount of crystalline phase resulting from the calcination process. X-ray powder diffraction analysis of simulated (non-radioactive) ICPP high alumina calcine shows that it consists of an amorphous phase plus three phases of varying crystal Unity; alpha, beta and gamma alumina. Subsequent quantitative x-ray analysis of the three crystalline phases was carried out using the internal standard method with sodalite as the standard phase. Limited peak selection for the alumina phases required a correction for the presence of a small sodalite peak contained within the analyzed gamma alumina peak (4° two-theta base width). Results of this study show that the calcine is composed of ∼90 weight percent gamma alumina, less than 3-4 weight percent each of alpha and beta alumina and the remaining 4-6 weight percent an amorphous component.