The temperature dependent contribution to the R-1 (E-2 <- (4)A(2)) linewidth in emerald, Be3Al2Si6O18:Cr-3, has been measured by employing spectral hole-burning, fluorescence line narrowing and conventional luminescence experiments. The contribution varies from 0.6 MHz at 6.5 K to similar to 420 GHz at 240 K and the line red-shifts by similar to 570 GHz. Above 60 K, the dependence is well described by a non-perturbative formalism for two-phonon Raman scattering. Below this temperature the direct one-phonon process between the levels of the split E-2 excited state dominates. However, it appears that a localized low-energy phonon leads to a deviation from the standard pattern at lowest temperatures. (C) 2013 Elsevier B.V. All rights reserved.