The exploration of the surface geology of Venus has been hampered by its inhospitable conditions and thick and opaque atmosphere. Fundamental properties, such as crustal composition and heterogeneity remain poorly constrained. Multiple analytical techniques are required to better understand its geology. A spectroscopy-based study laboratory study of the emissivity properties of Venus-relevant igneous rocks, measured at 440 °C by Dyar et al. (2020b; https://doi.org/10.1029/2020GL090497) shows that the use of multiple atmospheric windows in the 1-µm region can provide strong constraints on the FeO content of Venus-relevant igneous rocks, and by extension, the type of igneous rock. These results will improve our ability to map the surface geology of Venus remotely.