Luminescence emission bands originating in colour centres produced in natur
al topaz have been detected. These bands are studied by steady-state and ti
me-resolved photoluminescence spectroscopy. We found that the energy of the
emitting bands are different in colourless samples and in samples submitte
d to treatment and depend on the treatment itself. Also, there is an emissi
on present in long-lived detection regimes, indicating the possible presenc
e of non-radiative processes. These results are analysed and a possible cor
relation between structural and colour changes resulting from the irradiati
on and annealing treatment is addressed. (C) 2000 Elsevier Science B.V. All
rights reserved.