Cleaning Treatments for Silver with Precipitated Calcium Carbonate

This poster, titled “Cleaning Treatments for Silver with Precipitated Calcium Carbonate”, is presented by Han Zhou, PhD candidate at the University of Amsterdam, at the ICOM-CC Metal Working Group 2025 interim meeting METAL2025. The study recognizes a lack of systematic evaluation of the short- (after cleaning) and long-term (after re-tarnishing) effects of cleaning treatments with precipitated calcium carbonate (PCC) on silver objects. The poster shows findings from a preliminary testing in collaboration with metals conservators from the Rijksmuseum, the Netherlands, including results characterized with confocal laser scanning microscope (CLSM) and scanning electron microscope (SEM) coupled with energy dispersive X-ray system (EDS). These results indicate that both original surface finish and cleaning treatment with PCC lead to different chemical pathways in the re-tarnishing process of treated objects. Further research in this direction is on-going.