Micro-Raman spectroscopy on pigments of painted pre-Islamic ceramics from the Kur River Basin (Fars Province, Iran): The case of manganese oxides identification
Abstract
Micro-Raman spectroscopy was used for the analysis of painted pre-Islamic ceramics from the Kur River Basin (Fars Province, Southwest Iran). A total of 21 sherds were analysed dating from the Neolithic to the Late Bronze Age and belonging to different ceramic wares and sites.
The main focus of this research was to identify the pigments used for the red and black decorations of the different ceramic wares from the Kur River Basin and to elaborate on the manganese identification and their differentiation through Raman spectroscopy. Haematite (α-Fe2O3) and manganese oxides could be identified as the main compounds for the decoration in the different ceramic wares, except for the Bakun ware in which also carbon black could be determined as a probable pigment for black decoration using micro-Raman spectroscopy.
The identification and discrimination of manganese oxides were a meticulous task due to the sensitivity of these materials to the laser power, which can provoke degradation. Nevertheless, Raman spectroscopy was successfully applied for the identification of spectral patterns of the ceramics and their attribution to several manganese oxides present in the decorative mixtures, such as jacobsite (MnFe2O4), bixbyite (α-Mn2O3) and hausmannite (Mn3O4).