Electrodiffusion (sweeping) is a post-growth treatment which allows the selective exchange of charge compensating intersititial ions in quartz. This technique is employed commercially to enhance the radiation hardness of the material used for precision oscillator crystals. Most as-grown quartz contains substitutional Al3+ with an interstitial alkali providing the charge compensation. Additional unidentified sites also trap protons to form the OH--growth defects responsible for several IR absorption bands. When thermally released from their trapping sites, the intersitials can migrate along the large c-axis channels. Therefore, if the sample is heated with an electric field applied along the c-axis, the ions can be swept out and replaced either by protons from the surrounding atmoshpere or by the desired alkal i from a salt electrode. In order to better understand the electrodiffusion, we are systematically investigating various aspects of the process. The apparent ionic conductivity data taken as the swept sample is cooled usually shows a curved log( T) vs 1000/T plot. The conductivity of H+ in is much less than that of the lithium or sodium. The activation energies at high temperatures tend to be lower than those found from the low temperature data. The exponential prefactors are considerably larger than the values predicted for a given aluminum content and reasonable estimates of the attack frequency and jump distance. It seems likely that an additional source of mobile ions is present. The peak or plateau observed during the warm-up period for air or hydrogen sweeping appears to be caused by the transition from conduction primari1y by a1ka1i s to conduction by protons.