Viscosity-temperature relationships at 1 atm in the system nepheline-diopside

Abstract The viscosities of melts at 1 atm in the system nepheline-diopside have been measured using rotational and beam-bending techniques. At high temperature, melt viscosities decrease with increasing diopside component. This decrease in melt viscosity can be attributed to a reduction in the size of the flow units resulting from an increase in the number of nonbridging oxygens per tetrahedron. The low-temperature viscosity minimum at intermediate compositions develops as a consequence of the different viscosity-temperature profiles of nepheline and diopside melts.