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In this paper, possibilities and limits of the application of REE3+ luminescence (especially the Nd3+4F3/2 → 4I9/2 emission) as structural probe are evaluated. Important factors controlling the Nd3+ luminescence signal are discussed, including effects of the crystal-field, crystal orientation, structural state, and temperature. Particular attention was paid to the study of the accessory minerals zircon (ZrSiO4), xenotime–(Y) (YPO4), monazite–(Ce) (CePO4) and their synthetic analogues. Based on these examples we review in short that (1) REE3+ luminescence can be used as non-destructive phase identification method, (2) the intensities of certain luminescence bands are strongly influenced by crystal orientation effects, and (3) increased widths of REE3+-related emission bands are a strong indicator for structural disorder. We discuss the potential of luminescence spectroscopy, complementary to Raman spectroscopy, for the quantitative estimation of chemical (and potentially also radiation-induced) disorder. For the latter, emissions of Nd3+-related centres are found to be promising candidates.

The accumulation of structural damage that is created in minerals upon corpuscular irradiation, has two apparently contrarious effects on their luminescence behaviour. First, irradiation may cause the generation of luminescent defect centres, which typically results in broad-band emissions. Such defect emissions are characteristic of low levels of radiation damage. Second, radiation damage depletes in general the luminescence of minerals, which is associated with broadenings and intensity losses of individual emission lines. Minerals that have suffered elevated levels of irradiation hence tend to be virtually non-luminescent. This review paper aims at giving an overview of the possible correlations of radiation damage and emission characteristics of minerals. After a brief, introductory summary of the damage-accumulation process and its causal corpuscular radiation, an array of examples is presented for how internal and/or external irradiation may change appreciably the emission of rock-forming and accessory minerals. As a detailed example for the complexity of changes of emissions upon damage accumulation, preliminary results of a case study of the photoluminescence (PL) of synthetic CePO 4 irradiated with 8.8 MeV He ions are presented. Irradiation-induced spectral changes include (i) the initial creation, and subsequent depletion, of a broad-band, defect-related PL emission of orange colour, and (ii) gradual broadenings and intensity losses of PL lines related to electronic transitions of rare-earth elements, eventually leading to gradual loss of their splitting into multiple Stark levels (shown for the 4 F 3/2 → 4 I 9/2 transition of Nd 3+).

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