Mineralogy and technological analysis of ceramics (on materials from medieval sites of the Nomi-Western Ladoga Area)
Summanen I. M., Chazhengina S. Yu., Svetov S. A.
Zapiski RMO (Proceedings of the Russian Mineralogical Society). 2017. V. 146. N 3. P. 108-123
The paper concerns results of mineralogical analysis application towards the study of ceramic production technology in the North-Western Ladoga area during the Middle Ages. The data on chemical and mineral composition of clays and nonplastic tempers used in the ancient pottery allowed to determine technological specificity in the ceramic paste preparation and firing conditions. The most part of ceramics was made from domestic raw materials mined in close vicinity to dwelling sites. Ceramic paste for predominate types (II—VI and the earliest group) of grey-burning vessels was composed of iron-bearing illite and montmorillonite clays with addition of tempering admixture—sand or crashed rock, both of which are divided into several types according to its mineral composition and origin. The firing of ceramics usually took place in oxidizing atmosphere at the temperature of 900 °C and obviously did not last long. Several vessels made of kaolinite (light-burning) clays and imported ware were exposed to higher temperatures which possibly gives evidence of nonlocal origin of their production. It is supposed that these features combined with data on morphology and typology of ceramics point at the fact that there was no single centre of pottery production in the North-Western Ladoga area. It seems that pottery making was a kind of a seasonal craft.
Key words: clay minerals, ceramics, North-Western Ladoga area, scanning electron microscopy, Raman spectroscopy, differential thermal analysis, X-ray diffraction.