The crystalline quality of large grain size Cd1-xZnxTe with high Zn concentrations(0.45 < x < 0.85) grown by a zone melting process was investigated using photoluminescence, X-ray diffraction, optical transmission and micro-Raman measurements. We have found that extrinsic and intrinsic factors lead to Zn segregation encountered in both the radial and the longitudinal directions. The degree of segregation depends on the nominal Zn concentration. In addition, small precipitates of tellurium are found in the regions with low Zn concentrations in the solid solution. Such precipitates are absent in regions with high Zn concentrations.