“…The performance of these optics is outstanding, but from a pragmatic standpoint there is a problem: each such optic typically covers a limited energy range at useful Bragg angles, and consequently both synchrotron endstations and laboratory-based facilities must purchase or fabricate a suite of SBCAs based on different orientations of Si, Ge, and other perfect crystals (Gog et al, 2013(Gog et al, , 2018Yavas et al, 2007Yavas et al, , 2017 to cover the various fluorescence lines of any significant number of elements. These considerations are compounded at the numerous synchrotron endstations that seek to measure the most dilute systems or processes with small cross-sections and therefore multiplex several analyzers to increase solid angle for applications in resonant and nonresonant XES (Bergmann, Horne, Collins, Workman, & Cramer, 1999;Duan et al, 2017;Gallo & Glatzel, 2014;Glatzel & Bergmann, 2005;Gog et al, 2013;Lancaster et al, 2011;Pollock & DeBeer, 2011;Rovezzi et al, 2017;Sala et al, 2018;Sokaras et al, 2013;Verbeni et al, 2005;Zeeshan et al, 2019) and in studies of nonresonant inelastic X-ray scattering (Bradley et al, 2010;Fister et al, 2006;Huotari et al, 2017;Mao et al, 2003;Verbeni et al, 2009). This problem motivates us to study muscovite mica (henceforth -‗mica'‖) as a candidate diffractive material in SBCAs for XES.…”