Fig. 2: Effect of cooling rate on replicates of AR2 synthetic pigment.
From: Assessment of process variability and color in synthesized and ancient Egyptian blue pigments
a Photos of synthesis process showing ground precursors, the reacted pigment, the “loaves” after they easily separate from the porcelain crucibles (indicating minimal interaction), and the resulting ground pigments for samples cooled in air versus slowly cooled in a furnace. b XRD with ZnO external standard demonstrating increase in cuprorivaite fraction (+70% per Rietveld refinement) at the expense of amorphous Si-O and SiO2 when cooled slowly. Three dominant reflections of cuprorivaite are marked by asterisks. c Comparison of generalized cooling rates is demonstrated here.
