Ion implantation was used to introduce Pb into the mineral. Diffusion profiles were obtained using Rutherford back-scattering. The results for 600 to 900C were described by:

D(cm2/s) = 1.27 x 10-4 exp[-54.6(kcal/mol)/RT]

This suggested that radiation damage induced by ion implantation had little effect upon the Pb diffusion.

D.J.Cherniak, W.A.Lanford, F.J.Ryerson: Geochimica et Cosmochimica Acta, 1991, 55[6], 1663-73