  We present broad-band 24, 70 and 160 micron photometry, 5-35 micron and 55-90
micron spectra of the eruptive variable V4332 Sgr from Spitzer observations.
The distinguishing feature of the 5-35 micron spectrum is an unusually broad
absorption feature near 10 micron at the position generally associated with
silicate-rich dust. Through radiative transfer modeling, we show that this
broad feature cannot arise from silicates alone but requires the inclusion of
alumina (Al2O3) as a dust condensate. The case for including Al2O3 is
strengthened further by the presence of the AlO radical, a potentially
important molecule in forming Al2O3. The present detection indicates that
porous alumina manifests itself through a broadening of the 9.7 micron silicate
feature and additionally displays, on the shoulder of the silicate feature, a
component at ~11.5 micron. We discuss how further observations of V4332 Sgr may
have the potential of verifying some general predictions of the dust
condensation process.
