X-ray diffraction, infrared spectroscopy, and thermal methods of analysis were used to resolve conflicting statements in the literature on the thermal decomposition of dawsonite (NaAl(OH)/sub 2/CO/sub 3/). By 350/sup 0/C the dawsonite structure collapses and water equivalent to the hydroxyl group and a large portion of the carbonate CO/sub 2/ are lost. This decomposition product then gradually loses the remainder of the CO/sub 2/ and remains amorphous until crystalline NaAlO/sub 2/ is formed at approximately 670/sup 0/C.