A Technological Study of Making and Executing Raised and Gilded Ornaments on Mina i Wares from the Medieval Islamic Period in Iran

Enamel-painted ceramic from the medieval Persia (so-called haft rang/ mina’i ware) refers to a group of Islamic ceramics believed to have originated at late Seljuk and early Kharazmshahid dynasty (1179-1219 A.D.) in Iran. These wares characterized by stonepaste body and polychrome overglazes which represent. mina’i ceramic is one of the most important types of Islamic ceramic productions and identified by stonepaste body and multicolored polychrome over-glazes which represent figural, geometric and floral designs as well as calligraphic inscriptions. Additionally, mina’i wares are in some cases enlightened as applied relief and gilded surface. The style can be found in numerous forms including bowls, ewers, cups, beakers, jugs, inkstands and tiles. They are often referred to as “Haft-Rang” (seven color) ceramics due to their polychromic character. The colors were red, brown, cobalt blue, green, black, white and gold. It was believed, until quite recently, that one of these seven colors, namely cobalt blue, was painted not over, but in the glaze, and all the others were painted over. Suggested production centers for mina’i are Sava, Rayy and Kashan. While stylistic arguments have attributed the classification of objects to each of these sites, there is little archaeological evidence to support any of the claims. It has been argued that their style and imagery are reflected from Islamic manuscripts and wall paintings. Mina’i wares are very interesting to research not only in term of ceramic history and painting, but in Islamic ceramic technology. Much of our current understanding of minai techniques, and of medieval Islamic ceramic technology in general, comes from the only known treatise was written in 1301 A.D (70 A.H) by Abul'-Qasim Kashani. It is said that the "seven-colored technology passed into oblivion" by the time of the treatise. The study focuses on literature review and on observing the visual samples. Here four pieces of mina’i ware were sampled from Rayy and Alamut castle in Iran, which has been investigated through surface analytical techniques such as scanning electron microscopy complemented with energy dispersive X-ray spectrometers (SEM-EDX) and particle induced X-ray emission (micro-PIXE) and micro-RBS to characterize and identify the applied relief layers and gilding surfaces. This research focuses on defining the compositions of these surfaces. Interpretation through analytical methods allows obtaining more information about the historical methods and several layers that show technological evidence of overglaze method in mediaeval Persia. This paper focuses on defining the elemental composition of gold findings and relief in order to identify gilding process and the gold/ceramic adhesion mechanism. The results support that gilding decoration was using both mechanical as well as thermal process for adhesion mechanisms between gold leaf and its substrate. The other result suggests that reliefs were added over the base glaze layer to be observed between the body and the applied relief.