Water solubility in quartz and its influence on ductility

The deformation of wet synthetic quartz at moderate T is accompanied by a continuous change of the state of dispersion of H (sub 2) O; other relevant parameters of the deformation process are affected by this phenomenon. The solubility of H (sub 2) O in quartz as a function of P at 700 degrees C has been characterized experimentally. Wet samples have been annealed at this T at various P and then checked by TEM for precipitation of H (sub 2) O. It is found that the solubility increases with P. Wet quartzes were then deformed with a homogeneous H (sub 2) O content at P-T conditions: 1) lower than the equilibrium concentration, and 2) only slightly larger. Only glide is seen in the first case, but in supersaturated samples dislocation climb is active from the beginning of deformation and leads to a markedly lower flow stress.