American Mineralogist, Volume 82, pages 1079–1090, 1997

Surprisingly, this is not found in a com- the extent of equilibration between the host and lamellae parison of the Ca content of the late-stage 101 discs with and document the chemical zonation within the host that of an earlier ‘‘100’’ lamella (Table 1, Fig. [...] Schematic distribution of the Ca content in the cummingtonite host and the two hornblende lamellae systems on the basis of the AEM data. [...] The interfacial energy term increases contents of the 101 discs is that the cummingtonite be- at constant T with the curvature of the interface between tween the larger 100 lamellae had excess Al relative to precipitate and host, therefore the free energy increases Ca before the precipitation of the 101 discs. [...] During growth of the 101 discs, the with the effect increasing with the decreasing size of the Ca content of the host cummingtonite was depleted leav- precipitates. [...] Following the formation of disc-shaped 101 horn- The importance of the Gibbs-Thomson effect decreases blende lamellae, the factors that controlled the concentra- as size (radius of curvature) of the precipitates increase.