Emission spectra for different melt compositions at R = 800. The shown planets are: TOI-1807 b; 55 Cnc e; HD 806563 b. For each planet different colours indicate varying melt compositions, while the black curves represent Bulk Silicate Earth melts. Corresponding temperature profiles for each of the compositions are show in the inset. The blue shaded region represents variation in surface temperature, which in this case is largest between Bulk Silicate Earth and Oceanic comps.