Diffusion of Ar in optically clear natural and synthetic quartz crystals were examined at 500 to 1200C by treating polished specimens in pressurized Ar (1-185MPa) and characterizing the resulting diffusive-uptake (or subsequent diffusive-loss) profiles using Rutherford back-scattering spectroscopy. The Ar diffusivity was reasonably well described by:

D(m2/s) = 8.2 x 10-19 exp[-6150/T]

No effects of crystallographic orientation or quartz structural form (α or β) were discernible.

E.B.Watson, D.J.Cherniak: Geochimica et Cosmochimica Acta, 2003, 67[11], 2043-62