Comparison of low-temperature with high-temperature diffusion of sodium in albite

Abstract

Diffusion of sodium in albite from Amelia County, Virginia, was examined at high and intermediate temperatures by means of the sectioning technique and at low temperatures by means of an exchange technique. These studies indicate that diffusion is heterogeneous at low and intermediate temperatures, but goes to volume diffusion at high temperatures. Apparent diffusion coefficients of the order of magnitude of 10 −18 cm 2/sec and an activation energy of approximately 3000 cal/mole sodium are determined for the low-temperature movement. An activation energy of approximately 35 kcal/mole sodium is determined for the high-temperature movement.