In this article we report the growth and optical defect characterization of a novel family of alkali halide crystals, produced by the mixing of four ionic salts. These quaternary crystals imply the existence of four ternary crystals, one of these recently studied. The characterization is applied to two crystals with different component concentrations, one of these with a Europium impurity (an impurity with high optical sensitivity). We obtain the lattice constant by X-ray diffractometry. The optical absorption spectra of irradiated crystals show a single F band. The Generalized Vegard's law, applied to the novel ternary system recently studied, was extended to the quaternary crystal. Good agreement with the experimental results was obtained.