This work presents an investigation of naturally and experimentally unaltered and altered monazite-(Ce) and xenotime-(Y), as well as secondary phases and synthetic REE phosphates ( and ) with Raman microspectroscopy, using 488 nm, 532 nm, 633 nm and 780 nm excitation lasers, supplemented by electron probe microanalysis (EPMA) and laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS). Monazite-(Ce) spectra of the 532 nm laser from experimental products display a wide range of band positions of the v1() symmetric stretching band from 962 to 981 . Secondary fluorcalciobritholite spectra display a prominent band at 962–965 , a broader band at ca. 860 and broad distinct luminescence effects at mid-range. Xenotime-(Y) spectra from experimental products display only minor spectral changes, except for a few spectra near secondary Y-rich fluorcalciobritholite. Spectra of Y-rich fluorcalciobritholite from 532 nm laser display characteristic broad luminescence effects at the range of 1500–3000 , including a strong luminescence band at ca. 2600 ( electronic transition), and are accompanied by a broad band at 974 (488 nm laser) and 964 (633 nm laser). The characteristic changes in monazite-(Ce) spectra near secondary phases are emphasised with hyperspectral maps and EPMA-WDS X-ray compositional maps, which provide spatial context and reveal underlying interferences, important to be noted, when evaluating altered minerals. In all cases, ex-perimental and natural, high values of the full width at half maximum (FWHM) of the v1() band of unaltered monazite-(Ce) domains represent moderate radiation damage. In contrast, lower FWHM values were observed in altered domains. This work expands the Raman database onto examples of naturally and experimentally altered monazite-(Ce) and xenotime-(Y) enabling the identification of internal structural changes in unaltered and altered domains and differentiation of monazite-(Ce) or xenotime-(Y) from fluorcalciobritholite, Y-rich fluorcalciobritho-lite and other secondary phases.