Copper and Bronze in Art: Corrosion, Colorants, Conservation

Abstract

This 190 year review of the literature on copper and its alloys integrates the information on pigments, corrosion products and minerals that are usually considered separately though they are often the same compounds. The various environmental conditions to which copper alloy objects may be exposed including burial, outdoor, and indoor museum environments and the methods used to conserve them are discussed and information is included on ancient and historical technologies, the nature of patina as it pertains to copper and bronze and the use of copper corrosion materials as pigments. Chapters are organized primarly by chemical corrosion products and includetopics such as early technologies, copper chlorides and bronze disease, the chemistry and history of turquoise, Egyptian blue and other synthetic copper silicates, the organics salts of copper in bronze corrosion and bronze patinas. A detailed survey of conservation treatments for bronze objects is also provided. Four appendices cover copper and bronze chemistry, replication experiments for early pigments recipes, a list of copper minerals and corrosion products and X-ray diffraction studies. -- ICCROM