We synthesized Ag 3 Au(Se,Te) 2 alloys by slow cooling from the melt, leveraging our experience with the parent compounds, Ag 3 AuSe 2 and Ag 3 AuTe 2 . Detailed synthesis and characterization of these chalcogenides are available in our previous publications. We anticipated the melting points of Ag 3 Au(Se,Te) 2 alloys to align with those of fischesserite and petzite due to their similarity in chemical composition and crystal structure. Correspondingly, heating the reactants to 800 • C and slow cooling yielded ingots that resembled the parent compounds with a metallic luster, as presented in Figure . Refinement to the collected PXRD patterns verified single phase product in alloys with x = 0-0.75. However, samples with x = 0.9-1 showed 3-7% trace impurities of gold and binary metal tellurides by weight. The respective refined phase fractions are reported in Figure and.