Preliminary analytical and transmission electron microscopy (AEM and TEM) results for a small suite of natural perovskites are reported in this paper and discussed in relation to previous work. We show that perovskite compositions in Synroc and tailored ceramics plot within the known fields of natural perovskite compositions. AEM analyses and electron diffraction work on selected samples indicate that they are predominantly stoichiometric variants of the cubic perovskite structure. Geochemical alteration was observed in one sample of loparite from Bratthagen, Norway. The primary result of this alteration was leaching of Na from the A-site. Although sufficient alpha-decay dose levels for complete amorphization are not realized in this suite of samples, the available data bracket the beginning of the crystalline-amorphous transformation at doses that are ∼ 2-4 times greater than those of zirconolite of similar age. These results may be due to fundamental differences in the damage annealing rates of perovskite and zirconolite.