Glass forming ability and crystallisation behaviour of sub-alkaline silicate melts

These results may be used to retrieve the solidification conditions of aphyric, degassed and oxidised lavas; in addition, our data provide general constrains on the crystallisation kinetics of natural crystal-bearing silicate melts erupted on Earth (e.g. lavas with phenocrysts). The relationship between crystal content and cooling rate suggests that the solidification path induced by degassing can be also complex and nonlinear. The growth of crystals with size up to 1 mm from a nearly anhydrous superheated silicate melt indicates that variable cooling conditions of lavas have to be accounted to discriminate among minerals formed before, during and after eruptions. Moreover, our results can be used to design glass-ceramics from naturally available easy to find, low-cost starting materials.