S2: Water Rock Interaction (Special Session)

[S2-03] Hyalite-like spherules produced from silica-saturated hydrothermal fluid

*Hiroshi Isobe¹, Shosei Ieda² (1. Kumamoto Univ. Fac. Adv. Sci. Tech., 2. Kumamoto Univ. Fac. Sci.)

Keywords: hyalite, hydrothermal fluid, amorphous silica, andesite

Hyalite is a clear amorphous hydrous silica with spherical or conchoidal shape related to volcanic fluids. In this study, hydrothermal reaction of powdered andesite with silica-saturated fluid at 250°C produced clear spherules of pure SiO₂ with quite a similar shape and texture to natural hyalite.