  We present high resolution optical spectroscopic observations of IRAS
09425-6040, a peculiar, extremely red, C-rich AGB star showing prominent O-rich
dust features in its ISO infrared spectrum attributed to crystalline silicates.
Our analysis shows that IRAS 09425-6040 is indeed a C-rich star slightly
enriched in lithium (log (Li/H) + 12 ~ 0.7) with a low 12C/13C = 15+-6 ratio.
We also found some evidence that it may be enriched in s-elements. Combining
our results with other observational data taken from the literature we conclude
that the star is possibly an intermediate-mass TP-AGB star (M > 3 M_sun) close
to the end of its AGB evolution which may have only very recently experienced a
radical change in its chemistry, turning into a carbon-rich AGB star.
