The enduring secret of Meissen Porcelain

Prior to their restoration the porcelain bulks of 34 pieces from various 18th century authentic Meissen objects were studied by proton beam analysis. In either case attention was paid that the proton beam touches only the area of fracture. Thus, possible contributions from residues of surface glaze to the measured spectra were excluded. The chemical compositions obtained by light element (Na-Si) plus heavier element analysis represent quiet consistent mixtures of porcelain primary material. This finding reflects the consistent keeping of recipes and raw materials for Meissen porcelain production already at that time. The technology of surface glazing, by contrast, makes use of modified ingredients. It is shown that non-destructive analysis of intact glazed porcelain does not stand for the bulk material composition, hence may pretend wrong conclusions if bulk analysis is of interest.
The proton beam of 4 MeV-energy (Rossendorf 5 MV Tandem accelerator) leaves the vacuum beam line onto air and may hit unique objects without sampling. Extremely low beam intensities and short irradiation times ensure non-destructive analysis of the valuable objects. The chemical elements of the irradiated material respond emitting characteristic radiations. They are detected simultaneously in order to get non-destructive and complete composition analysis using the established ion beam techniques PIXE (Particle induced X-ray Emission), PIGE (Particle Induced Gamma-ray emission) and RBS (Rutherford Backscattering Spectrometry).