Ancient potsherds, paleo-sols, and modern soil samples from the Gorgan plain Northeastern Iran have been characterised by Mössbauer spectroscopy, X-ray diffraction, elemental and mineralogical analysis. The clay and other mineral species, and especially the iron-bearing minerals in the soils were identified, Test firings were carried out in the temperature ranges 650-115 C in air or in a reducing atmosphere. The quadrupole splittings of the ferric and ferrous doublet are functions of the firing temperature used by the ancient potters, can be estimated. Sherds of the red and grey ware from Turen Tepe IIA(3000-2 800 B.C.) were examined, and respectively found to be oxidized or reduced compared with the soils. Firing temperatures of (1 050 ± 50)° C and (980 ± 50)° C were deduced for samples of the two types of pottery thus the grey ware could be fired at a temperature of 50 to 100° C. lower than the red ware.