  We present pre-perihelion infrared 8 to 31 micron spectrophotometric and
imaging observations of comet C/2012 K1 (Pan-STARRS), a dynamically new Oort
Cloud comet, conducted with NASA's Stratospheric Observatory for Infrared
Astronomy (SOFIA) facility (+FORCAST) in 2014 June. As a "new" comet (first
inner solar system passage), the coma grain population may be extremely
pristine, unencumbered by a rime and insufficiently irradiated by the Sun to
carbonize its surface organics. The comet exhibited a weak 10 micron silicate
feature ~1.18 +/- 0.03 above the underlying best-fit 215.32 +/- 0.95 K
continuum blackbody. Thermal modeling of the observed spectral energy
distribution indicates that the coma grains are fractally solid with a porosity
factor D = 3 and the peak in the grain size distribution, a_peak = 0.6 micron,
large. The sub-micron coma grains are dominated by amorphous carbon, with a
silicate-to-carbon ratio of 0.80 (+0.25) (- 0.20). The silicate crystalline
mass fraction is 0.20 (+0.30) (-0.10), similar to with other dynamically new
comets exhibiting weak 10 micron silicate features. The bolometric dust albedo
of the coma dust is 0.14 +/- 0.01 at a phase angle of 34.76 degrees, and the
average dust production rate, corrected to zero phase, at the epoch of our
observations was Afrho ~ 5340~cm.
