Laser-induced time-resolved luminescence as a means for discrimination of oxidation states of Eu in minerals

Simultaneous detection of divalent and trivalent europium is investigated by time-resolved laser-induced luminescence in a number of minerals. The selectivity of detection is possible by using different time delays after excitation, different gate widths and different excitation wavenumbers. This technique allows detection of Eu luminescence in minerals in which it is hidden by other luminescence centers in the steady-state luminescence spectra. In such a manner we detected Eu²⁺ and two different Eu³⁺ luminescence centers in apatite and fluorite, Eu²⁺ and Eu³⁺ luminescence in datolite and danburite, and Eu³⁺ luminescence in zircon and calcite.