عنوان مقاله [English]
Color variation and rainbow-like look in Mina`i glaze have made this glaze one of the most attractive ornaments. The glaze includes a wide range of yellow, blue, green, brown, purple, black, white and red hues which is occasionally accompanied with gilding and Zarrin fam. The Minaʹi glaze, as art and science, has always historically and technically been of interest to scholars and artists. This art is based on the science of alchemy. In the field of pottery science, known as alchemy in the past, there are limited resources. In this area, there are two reliable sources in Persian language with titles “Arayes al-Jawahir and Nafayes al-Tayeb” by Abolqasem Kashani and “Javaher Name Nezami” by Mohammad ibn Abi al-Barakat Johari Neyshaburi. In the "Arayes al-Jawahir and Nafayes al-Tayeb" book, there are references to Minaʹi glazes and according to Abolqasem Kashani, its other names are “seven colors” and “two firing glaze”. Another book is Javaher Name Nazami which was written in 592 AH, and probably is the oldest and the closest Persian source to the golden age of Iranian pottery, including years of pottery and Mina’i glaze production.
The production year of this ornamental style of pottery, according to the existing inscriptions on ceramic works, dates back to the late sixth century and the early seventh century. Simultaneous with the era, Mohammad Neishaburi has presented a precious text in the fourth chapter of his book titled “the variety of colors using on glassware and ewer types Qashy, Isfahani, Shamy and Chinese and otherwise”. He has written on various combinations and explanations about this technique which they used in pottery and glassware in the past. The colors include golden, yellow, red, black, silver, blue, green and white as well as other colors. Among the compositions, two types of yellow with the title “Lune zard” are observed which appear to be different hues of yellow. The following question is raised that what is the result of the empirical experiments of the two different combinations presented in Javaher Name Nezami with the title “lune zard”, and how are they manifested on Minaʹi pottery?
The purpose of this research is to study and compare the yellow color compounds in this book and the experimental results of their manufacture as well as the visual comparison of the colors obtained with the colors used in the pottery of this era in order to verify the accuracy of these compounds, both through testing and through visual matching to samples of Mina`i pottery.
In the present research, two different combinations of yellow were selected from the Javaher Name Nezami book and analyzed with the aim of matching them. In the research process, the compounds presented in the text of Javaher Name Nezami book were equated with modern materials and vocabulary after studying the structure. Based on the data and findings from validated books, the existing compounds were tested experimentally and in vitro. The two compounds were combined with non-industrial vinegar after extensive abrasion and applied with a brush on a body covered with alkali-boron glaze .Then, they were heated at four temperatures in the oxidation kiln: 550, 500, 580 and 630 ° C (It should be noted that all tests are the same in terms of type of ingredients, type of kiln and method of manufacture).
This study is a combinational research; part of its theoretical foundations are based on a descriptive method, and in empirical parts expresses information about the accuracy of the yellow color compounds by using experimental method and visual comparison of obtained yellow hues with samples of Minaʹi pottery with a descriptive-analytical method. The primary data in descriptive parts of research were collected through library research, with emphasis on the Javaher Name Nezami book and ancient texts. Pictures of Mina`i pottery are collected from domestic and foreign museums, and information in the experimental part of the research through observation. In the end, this research has been evaluated qualitatively. The results of the experiments show two different yellow hues in two different combinations in military jewelry; yellow- olive and yellow- orange. The colors were obtained at temperatures of 580 and 630 ° C in oxidation environment using overglaze method similar to Mina’i glaze of the Seljuks and the Khwarazmian.
Comparing the colors obtained from the experiments and samples of the Minaʹi pottery from the 6th and the 7th centuries AH, suggests similarities, indicating that the information in the book is correct, and with correct factors and materials including the precise selection and replacement of materials with modern ones, observing the proportions presented in the text, the choice of the appropriate base for the glaze, providing the environment and the conditions of oxidation as well as the appropriate temperature in accordance with this ancient text, different color combinations similar to the Minaʹi pottery of the 6th and the 7th centuries are produced.