Many forms of low temperature alumina have been identified [1]. These are collectively referred to as transitional forms. The particular form depends strongly on the starting material (e.g., hydrated, thermally oxidized, alkoxide, etc.), the impurities present, and on thermal history. Although different forms of transition alumina are sometimes referred to as phases, none can be considered a true polymorph of corundum, i.e., α-alumina. Transformations from one form to another which occur upon heating are not reversible, although they are quite reproducible [2]. These different transitional structures are therefore considered to comprise different states of reordering. Figure 1 is a compendium of powder x-ray diffraction patterns from all known transitional aluminas and several aluminum hydroxides [3]. It i.s obvious that there are several crystallographic spacings which are nearly common to all forms.