A paper led by Mr. Shima, a graduate of our laboratory, on the formation conditions of metastable α-cristobalite has been published in Journal of Mineralogical and Petrological Sciences.
Cristobalite is one of the polymorphs of silica. In this study, we compared the crystallization of α-cristobalite from heated amorphous silica with and without vanadium pentoxide (V2O5) as a flux. Without the flux, crystallization occurred at 1200°C, whilst the addition of V2O5 lowered the formation temperature to 1000°C and produced α-cristobalite crystals with well-developed facets. V2O5 is thought to induce partial melting, which lowers the activation energy for crystallization and promotes crystal growth. These findings would lead to our better understanding of the formation of metastable SiO2 polymorphs and improved control of crystal synthesis.
Shima T., Komatsu K., and Kagi H. (2026) Formation conditions of metastable α-cristobalite from amorphous silica with and without V2O5 flux. Journal of Mineralogical and Petrological Sciences, 121:0003.