Porcelain Analysis and Its Role in the Forensic Attribution of Ceramic Specimens

Book excerpt: The material for this book arose from the author’s research into porcelains over many years, as a collector in appreciation of their artistic beauty , as an analytical chemist in the scientific interrogation of their body paste, enamel pigments and glaze compositions, and as a ceramic historian in the assessment of their manufactory foundations and their correlation with available documentation relating to their recipes and formulations. A discussion of the role of analysis in the framework of a holistic assessment of artworks and specifically the composition of porcelain, namely hard paste, soft paste, phosphatic, bone china and magnesian, is followed by its growth from its beginnings in China to its importation into Europe in the 16th Century. A survey of European porcelain manufactories in the 17th and 18th Centuries is followed by a description of the raw materials, minerals and recipes for porcelain manufacture and details of the chemistry of the high temperature firing processes involved therein. The historical backgrounds to several important European factories are considered, highlighting the imperfections in the written record that have been perpetuated through the ages. The analytical chemical information derived from the interrogation of specimens, from fragments, shards or perfect finished items, is reviewed and operational protocols established for the identification of a factory output from the data presented. Several case studies are examined in detail across several porcelain manufactories to indicate the role adopted by modern analytical science, with information provided at the quantitative elemental oxide and qualitative molecular spectroscopic levels, where applicable. The attribution of a specimen to a particular factory is either supported thereby or in some cases a potential reassessment of an earlier attribution is indicated. Overall, the information provided by analytical chemical data is seen to be extremely useful for porcelain identification and for its potential attribution in the context of a holistic forensic evaluation of hitherto unknown porcelain exemplars of questionable factory origins.