X-ray Diffraction (XRD) analysis of cement process materials has grown beyond its roots in the laboratory to become an important tool for process control. Combined with its partners, XRF and CNA, these techniques can provide valuable process control information — essentially “new eyes” — to guide process control decisions. Important developments in the XRD analyzers have decreased analysis time from hours to minutes to provide quick results that enable timely process control decisions. XRD phase analysis can provide information to optimize combustion control, mix chemistry, cooler operation as well as additive mixtures in finish cement. The paper will provide an overview of all the XRF/XRD applications and then focus on the XRD process control opportunities.