The aim of this work is to study the structural characteristics and properties of the solid solution (Al,Cr)(2)O-3. XRD analysis, Al-27 MAS-NMR measurements, and microstructural characterization were used to determine the relationship between color and crystallochemical properties of the compounds formed, In particular, to determine more accurately the mechanism of solid solution formation above the miscibility gap of the system, the marker technique was used. In order to define the behavior of the system for temperatures below the miscibility gap at 1 bar pressure, the composition Al2O3:Cr2O3 1:1 was studied with high-temperature XRD.