Many fine-grained Ca-Al-rich inclusions in the Allende meteorite show a consistent pattern of mineralogic and textural zonation. The center, zone A, consists mostly of spinel, nepheline, Al-diopside and salite, with minor amounts of olivine, sodalite, grossular, anorthite, perovskite, and ilmenite. In most inclusions, these minerals occur as loosely packed, discrete, anhedral to subhedral grains with only minor intergrowth between phases. In the others, zone A is made of 5 to 30 μm-sized, spinel-centered, multi-rimmed objects, and of finer-grained, loosely packed, interstitial material. The intermediate zone, B, is characterized by the presence of hedenbergite and andradite (in addition to the minerals which occur in zone A) partially filling voids. One type of outer zone, C, consists mostly of intergrown olivine and nepheline with small ilmenite grains enclosed. The other type of zone C consists of symplectic texture with spinel rimmed by nepheline or anorthite, rimmed by Al-diopside. The textural and mineralogical similarity of zone A, except for the rimmed spinel objects, to altered areas of coarsegrained melilite-rich CAIs suggests that a similar open system alteration affected the fine-grained inclusions and that zone A's contained melilite before being completely altered to anorthite, grossular, nepheline and sodalite. By comparing the mineralogies before and after the alteration, some Ca must have evaporated from—and Si, Fe, Na and Cl condensed onto—the inclusions. Under conditions of low temperatures (<1000 K) and/or at H O ratios lower than the cosmic abundance, Ca is more volatile than Si due to the formation of gaseous Ca-hydroxides. The thermodynamic stability of minerals in zones A and B also indicates alteration at temperatures less than 1000 K. The mode of occurrence of hedenbergite and andradite in zone B implies that they are condensates deposited on the edge of zone A. It is likely that the Ca migrating out of the center of the inclusions and the Si and Fe migrating inward from the surrounding nebular gas coprecipitated according to the thermodynamic stability of these minerals. Zone C, on the other hand, most likely existed even before alteration, surrounding what is now zone A. However, the mineralogy of zone C appears to have changed by alteration: the zone C consisting of olivine, nepheline and ilmenite was probably a spinel-rich belt mantling the inclusion.