Mössbauer Spectroscopic and Chromaticity Analysis on the Colourative Mechanism of Ancient Goryeo Celadon from GangJin and Buan

In ancient G oryeo celadon excavated from the kiln sites in the G ang J in and B uan areas, the effect of the chemical composition and ionic state of F e on the colour was evaluated by M össbauer spectroscopy and chromaticity analysis. According to chromaticity analysis, the L * value (brightness) of the glaze was shown to be affected more by T i O 2 and M n O than by F e 2 O 3 , and the body was affected more by F e 2 O 3 than by T i O 2 . The a* value was found to be affected by F e 2 O 3 and T i O 2 in the glaze, whereas there was hardly any change in the body according to the composition. As for the b* value, changes due to the composition were shown to be smaller than those for the L * and a* values. According to the M össbauer spectroscopy results, as the quantities of T i O 2 and F e 2 O 3 are increased, F e 2+ / F e 3+ decreases; while the changes in F e 2+ / F e 3+ with M n O and P 2 O 5 are negligible. As the quantity of F e 2+ / F e 3+ increases, the a* and b* values decrease, which results in the change of colour from red–yellow to blue–green. The characteristic green colour can be attributed to increased L * (brightness) and decreased a* and b* values (blue–green shift) due to the reduced F e ion, which is mainly determined by the T i O 2 and F e 2 O 3 contents.