  We present SOFIA/FORCAST imaging of the circumstellar dust shells surrounding
the luminous blue variable (LBV) candidates MN 90 and HD 168625 to quantify the
mineral abundances of the dust and to constrain the evolutionary state of these
objects. Our image at 37.1 micron of MN 90 shows a limb-brightened, spherical
dust shell. A least-squares fit to the spectral energy distribution of MN 90
yields a dust temperature of 59 \pm 10 K, with the peak of the emission at 42.7
micron. Using 2-Dust radiative transfer code, we estimate for MN 90 that
mass-loss occurred at a rate of (7.3 \pm 0.4)x10^-7 M_sun/yr x (v_exp/50 km/s)
to create a dust shell with a dust mass of (3.2 \pm 0.1)x10^-2 M_sun. Our
images between 7.7 - 37.1 micron of HD 168625 complement previously obtained
mid-IR imaging of its bipolar nebulae. The SOFIA/FORCAST imaging of HD 168625
shows evidence for the limb-brightened peaks of an equatorial torus. We
estimate a dust temperature of 170 \pm 40 K for the equatorial dust surrounding
HD 168625, with the peak of the emission at 18.3 micron. Our 2-Dust model for
HD 168625 estimates that mass-loss occurred at a rate of (3.2 \pm 0.2)x10^-7
M_sun/yr to create a dust torus/shell with a dust mass of (2.5 \pm 0.1)x10^-3
M_sun.
