Advances in Achaemenid brick manufacturing technology: Evidence from the monumental gate at Tol-e Ajori (Fars, Iran)

A wide homogeneity is present for all the considered bricks: Ca-rich clays with quartz-rich temper were used, this possibly suggesting a common raw material origin. Firing temperatures interval was estimated around 850-900 °C. A multivariate data treatment (PCA and HCA analysis) was applied to the XRF data set acquired for both clays and bricks. PCA suggests that Polvar alluvial clays could be the source raw material for mostly of Tol-e Ajori's bricks and more than one clay deposit was probably used.