Results of transmission measurements for two macroscopic realizations of the metamaterial of diamond. Spectra are taken in two different directions of the lattice and for two different refractive indices $n=1.8$ and $n=2.1$⁠. The cubic samples have a side-length of 10 cm. The $Al2O3$ samples suffer from mechanical damage due to their brittleness, as exemplary shown in the inset image of the diamond in a). The peak position as well as the depth of the peak coincide well for a) Al₂O₃ in (100) and b) TiO₂ in (1$1¯$1) direction.