Structural Characterization of Steatite Vessels of Shadyakh by XRF, XRD and SEM Techniques

Using the stones to make tools and vessels dated back to Paleolithic and Neolithic periods. Stones so called soft stones, along with the alabaster, are one of the most famous stones that have been used to produce vessel in Near East, where they are in use currently in different applications. Soft stone vessels reach to highest level of flourishing during the Bronze Age and its geographical exchange area stretches from India in east to Syria in west. Iran, as one of the most important places of this kind of stones, was a potentially center in this trade and archaeological sites such as Tape Yahya and Konar Sandal in Kerman province are some of the most famous sites in making and exporting this kind of objects. Although soft stone vessel making continued during historical to Islamic era, but this industry has been neglected by researchers and archaeologist. In addition, until now morphological and artistic reports and archaeometry studies have focused only on Bronze Age vessels. During six seasons archaeological excavations at an Islamic Archaeological site called Shadyakh near to modern city of Neyshabur (about 2 km south east of Neyshabur), which its date goes back to Early and middle Islamic period, many cultural objects, like the pottery, glass, metal, bones, human skeletal, plaster, and architectural remains have been discovered. Beside of these samples, several pieces of soft stone vessels were discovered from several archaeological excavations. No evidence of workshop or crafting was reported and according to geological reports around this region, no outcrop of soft stone was seen. Although that these vessels are important, no study have yet been conducted on them. At this research, the vessels have been archaeometrically studied. The main objective of this research was to gain the information about the structural characteristics of soft stone vessels recovered from this site. Before this, Kohl and his collogues in 1979 carried an investigation on large amount of Bronze Age archaeological samples from Middle East. They found several main groups and a mine around Mashhad was recognized. Other researches on soft stones include Razani’s M.A and Imami and his colleague’s researches on new chlorite mines of Ashin; and Afshari Nezhad and Razani’s research on structural characterization and conservation of Jiroft cultural basin’s chlorite vessels. The only research on historical and Islamic soft stone vessels was about the effect of cooking conditions on structure of vessels. At this research, totally 16 samples from different seasons of archaeological excavations of Shadyakh were collected and analyzed by XRD, 4 sample analyzed by XRF, and 2 samples by SEM. The results of XRD analysis showed two main groups, while 21 trace elements and 11 chemical compound were detected by XRF. The raw data was studied by Excel statistic software. At this study, overlap graph was prepared according to finding difference or similarity between samples where the results show high similarity among the samples. The SEM and XRD results show that main compounds are Talc, Steatite, Soapstone, Clinochlore, Graftonite, Dolomite, Britholite and Clinochlore. All samples have these compounds, therefore, it could be concluded that Shadyakh samples come from one geological zone.