Maximum iron mass fraction of a planet formed near the iron evaporation front as a function of the Mg/Si ratio of the central star. These are the results of simulations using solar disc composition, α = 10⁻⁴ and u_frag = 5 m s⁻¹. The iron mass fraction of super-Mercuries and super-Earths (Adibekyan et al. 2021) as well as Mercury are included for comparison. The grey band and dashed line represent the range of Mg/Si values of super-Mercury host stars and the Sun, respectively.