Comparison of the measured MAC of the samples X5OA, X5OB, X4O, and X35 at 10 K with the M ACs calculated for cosmic dust models using Mie theory for spherical grains of 0.1 μm in size: astrosìl from (Li & Draine 2001) (red curve) and the two silicates from the THEMIS dust model (Jones et al. 2013): amorphous enstatite (cyan curve) and amorphous forsterite (green curve). We note that to be comparable with the experimental data, the MACs were modelled in PE and not in vacuum.