This dataset contains laboratory spectra of olivine and pyroxene in the mid-Infrared (MIR; 5-35 micron) wavelength region as described in Martin et al., (in rev). Files are labeled accordingly: mineral_smallest particle size_largest particle size_regolith porosity_measurement type OLV = olivine, PYX=pyroxene r = ambient reflectance, a = ambient emissivity, sae = simulated asteroid environment Example: The file labeled OLV_45_63_10_a.txt contains spectra of olivine, with 45-63 micron particle sizes, has 10% regolith porosity, and was measured in ambient emissivity.