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Example 3: The West Porch of the Cathedral of Meissen (Germany) Another example for the ancillary but indispensable function of X-ray diffraction analysis in combination with other microanalytical techniques for art historians and conservators is the examination of materials used for the polychromed sculptures at the west porch of the Protestant Cathedral of Meissen [5]. Restoration work on this porch and the pier sculptures concentrated on removing the overpainted layers of more recent origin with scalpels and pencutters. This work exposed extensive "original" paintings, but when comparing with the restoration data documented in the archives, doubts arose about their age. Stratigraphic examinations on polished cross sections of the paint layers and analytical investigations by means of optical emission spectroscopy and microchemical tests then exhibited different paint layers consisting of historical pigments such as vermilion (HgS), azurite [2CuC03 . CU(OH)2], verdigris (basic Cu acetate), and lead-tin yellow, a mixture of Pb2Sn04 and PbSnSi07. But at several parts of the object a turquoise paint layer mixed

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