The effect of zinc ions (Zn 2?) on the structure, morphology and optical properties of (Ca 1-x Zn x )WO 4 microcrystals with (x = 0, 0.01, 0.02, and 0.03) obtained by the microwave-hydrothermal method at 170°C for 1 h is reported in this letter. These microcrystals were characterized by X-ray diffraction (XRD), Rietveld refinement, energy dispersive X-rays spectroscopy (EDXS) and field emission scanning electron microscopy (FE-SEM) images. The optical properties were investigated by ultraviolet-visible (UV-Vis) diffuse reflectance spectroscopy and photoluminescence (PL)