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The 13th Conference of the European Ceramic SocietyLimoges 23rd-27th June 2013&#160;THEME J ‐ Archeo‐Materials1)      Title: Analysis on Ancient Celadon Pieces from Kiln Sites in Gangjin, KoreaAuthors: Hyunggoo No, Soomin Kim, Jongyoung Kim, Wooseok Cho, Ungsoo Kim (Korea Institute of Ceramic Engineering &#38; Technology)Presenting author:Dr Ungsoo KIMKorea Institute of Ceramic Engineering &#38; Technology, Icheon Branch, Icheon SOUTH KOREACeladon is a unique porcelain found in a small area of eastern Asia. Gangjin, which is a small town in the southern part of Korea, is known for celadon since Goryeo Dynasty (A.D. 918~1392). The celadon glaze was developed and refined during the 10th and 11th centuries in that area. Ancient celadon pieces excavated from Gangjin were analyzed for chromaticity, chemical composition, and microstructure. Mössbauer analysis was performed to investigate the electronic state of iron oxide in celadon samples. The microstructure of celadon bodies seem to be fully densified with round pores in the range of several to a few hundred microns. Well developed mullite crystals suggest firing process above the maximum temperature of 1200°c. Etching on the glaze with hydrofluoric acid reveals dispersed submicron droplet phase separated structure, in which the equivalent diameter of the droplets falls into the range of 10‐30 nm. Anorthite crystals were also shown to form in glaze layer. Mössbauer analysis shows that Fe2+/Fe3+ ratio is varying depending on the samples, and directly related to the chromaticity. With these results the feasibility of reproducing celadons was studied using the materials obtained from around the kiln sites.&#160;&#160;2)      Title: Effect of firing atmosphere and glaze thickness on the coloring of Goryeo Celadon&#160;Dr Jae‐Hwan PEEKICET, Traditional Ceramic Center, Icheon KOREAIn Korea peninsula, many Goryeo‐celadon relics have been excavated. The color values of celadon relics using colorimeter were evaluated. Although these relics were excavated in the same kiln site and period, they have different brightness and hue values. As expected, they have similar chemical compositions of body and glaze. So many studies were focused on color generating mechanism by iron ionic state in the glaze. As a result, they reported that the ferric oxide (Fe2O3) included in the glaze is changed into ferrous oxide during reducing firing process. But they did not quantitatively evaluate the effect of firing conditions and glaze thickness on the color value of celadon. So in this study, we tried to evaluate the residual oxygen state in glaze depending on the firing atmosphere.&#160;