Samples of neutron-irradiated α-Al 2O 3 were observed to exhibit an unusual form of decay of their absorption bands. A similar form of decay has been described in thermoluminescence theory, and has been labelled "anomalous fading". We believe that this is the first time that this decay has been observed in the absorption spectra of aluminium oxide. It takes the form of a linear decay as plotted on optical density vs log(time) axes, and it appears to be largely temperature-independent over the range studied, as is often the ease with "anomalous" fading. Experimental data are presented together with alternative theoretical models that predict this behaviour.