To explain the observed polarization levels, the disk must consist of relatively large (> 5 µm) silicate dust particles, which scatter light most strongly and polarize it more for forward scattering. (gemini.edu)
Dim objects called brown dwarfs, less massive than the Sun but more massive than Jupiter, have powerful winds and clouds — specifically, hot patchy clouds made of iron droplets and silicate dust. (sciencedaily.com)