  Combined ISO SWS and LWS spectroscopy is presented of the late WC-type
planetary nebula nucleus CPD-56 8032 and its carbon-rich nebula. The extremely
broad coverage (2.4-197 microns) enables us to recognize the clear and
simultaneous presence of emission features from both oxygen- and carbon- rich
circumstellar materials. Removing a smooth continuum highlights bright emission
bands characteristic of polycyclic aromatic hydrocarbons (hereafter PAHs) in
the 3-14 micron region, bands from crystalline silicates longwards of 18
microns, and the 43- and 62-micron bands of crystalline water ice. We discuss
the probable evolutionary state and history of this unusual object in terms of
(a) a recent transition from an O-rich to a C-rich outflow following a helium
shell flash; or (b) a carbon-rich nebular outflow encountering an O-rich comet
cloud.
