The article provides an in-depth analysis of the deteriorated green paint layers at the Maritime Station, focusing on the artwork by Almada Negreiros in Lisbon. The study reveals a complex composition of natural and synthetic pigments, including Fe-based pigments, calcium carbonates, and carbon black. Clinochlore, a mineral uncommonly reported for green pigments, was also identified. Various analytical techniques such as optical microscopy, micro-Raman spectroscopy, and micro-XRD were used to investigate the paint layers.
The research uncovered the presence of synthetic organic pigments, particularly Pigment Green 8, in several samples. Additionally, signs of bio-colonisation and bio-contamination were observed, possibly due to factors like high humidity and biodegradable materials. Calcium sulphates, specifically gypsum, were identified as the main agents causing powdering and flaking of the green paint layers.
Colorimetry and spectrophotometry analyses highlighted differences in chromatic coordinates and elements present in the paint layers. Elemental composition analysis using handheld EDXRF and VP-SEM-EDS imaging provided insights into decay phenomena and pigment composition. XRD analysis detected barite and gypsum, suggesting their original use as fillers or extenders in the paint layers.
Overall, the study offers a comprehensive understanding of the composition, deterioration mechanisms, and decay agents affecting the green paint layers at the Maritime Station. The findings contribute valuable insights into the conservation and restoration of this significant modern artwork, shedding light on the intricate materials and processes involved in its creation and degradation over time.
