Technical study of historical tiles of azure and yellow color Spectrum in mosaic and dual tiles

In Iranian architecture, colors were a powerful tool in design that, by using them correctly in decorations, added to the identity and impact of that space. One of the techniques of architects in decorating the space has been the use of complementary colors to create a proper harmony in the viewer's eyes. In this experimental-analytical study, CIE Lab analysis was used to quantitatively measure the complementary colors of azure and yellow historical glazes, And was tried to study the cause of different spectra of these two colors of mosaic and dual tile glazes by Edx analysis. also, petrography and Xrd analysis should be done on the tile biscuits. The results of the analysis showed that azure glazes are alkaline and cobalt is a color producer in all spectrums and lead has an effect on its intensity. Iron is present as one of the yellow color agents in all samples of yellow glazes Elements such as titanium, cadmium, tin, nickel, vanadium and lead antimony have been the cause of yellow color in various samples. And this has caused the different color tonality. Petrographic and Xrd results of tile biscuits indicate oxidation baking environment and baking temperature less than 800 degrees.