Potential of cathodoluminescence (CL) microscopy and spectroscopy for the analysis of minerals and materials.

The present study summarizes results of cathodoluminescence (CL) microscopy and spectroscopy applied to minerals and materials. CL can be used both in a purely descriptive way to detect and distinguish different minerals or mineral generations by their variable CL colours or as an effective method for spatially resolved analysis of point defects in solids by spectral CL measurements. The cathodoluminescence emission is in all cases either related to lattice defects (e.g. electron defects on broken bonds, vacancies or radiation induced defects) and/or to trace activator ions such as REE(2+/3+), Fe(3+), Cr(3+), Al(3+), Mn(2+), Pb(2+), Cu(2+), Sn(2+) or uranyl groups. CL spectroscopy is an outstanding method to characterize the degree of purity of materials or to detect trace elements in natural and synthetic minerals. In this way, alterations, diffusion of trace elements or formation of new phases are successfully detectable even in the case of materials with heterogeneous texture and high contents of non-crystalline phases.