  The most successful model of comet dust presents comet particles as
aggregates of submicron grains. It qualitatively explains the spectral and
angular change in the comet brightness and polarization and is consistent with
the thermal infrared data and composition of the comet dust obtained {\it in
situ} for comet 1P/Halley. However, it experiences some difficulties in
providing a quantitative fit to the observational data. Here we present a model
that considers comet dust as a mixture of aggregates and compact particles. The
model is based on the Giotto and Stardust mission findings that both aggregates
(made mainly of organics, silicates, and carbon) and solid silicate particles
are present in the comet dust. We simulate aggregates as {\bf Ballistic
Cluster-Cluster Aggregates (BCCA)} and compact particles as polydisperse
spheroids with some distribution of the aspect ratio. The particles follow a
power-law size distribution with the power -3 that is close to the one obtained
for comet dust {\it in situ}, at studies of the Stardust returned samples, and
the results of ground-based observations of comets. The model provides a good
fit to the angular polarization curve. It also reproduces the positive spectral
gradient of polarization, red color of the dust, and {\bf low albedo. It also
has the ratio of compact to fluffy particles close to the one found {\it in
situ} for comet 1P/Halley} and the mass ratio of silicate to carbonaceous
materials equal to unity that is in accordance with the elemental abundances of
Halley's dust found by Giotto mission.
