We propose to observe the Zodiacal background with SWS AOT6 along 
four sightlines to study the solid-state chemistry of the Solar
System dust disk at unprecedented resolution.  SWS is sensitive to the 
thermal emission down to at least 0.1 Jy, and we discovered narrow 
(probably crystalline) emission features overlying this continuum in 
a CUS calibration observation even at marginal S/N.  These features are 
out of the reach of P40 and C04 spectral resolutions, and have not 
been confidently identified with laboratory transmission spectra or 
astroidal features.  Sightlines will include high, intermediate, and
low ecliptic inclinations to separate asteroidal and cometary dust
components, avoiding the galactic plane itself.  Spectral coverage
is chosen to cover our current detections, the temperature-sensitive
region of the thermal emission, and the major silicates detected in 
closely-related environments.  At the required S/N, each sightline
will require 2.5 hours.  We request a total of 10 hours for this
project, which will substantially augment ongoing P40 and C04 
programmes and benefit studies of the dust disks around planet-forming
stars.