AbstractDegradation of archaeological artefacts sometimes leads to unusual corrosion products. Techniques have been used to analyse the upper disc of a rare Roman inkwell. Made of leaded bronze and decorated with silver and copper, the object was well preserved in spite of some changes. Corrosion products have been analysed and found to be mainly lead corrosion products. Among them, lead sulphates and lead phosphates such as anglesite and hydroxypyromorphite have been identified and detected all over the surface. The object was discovered during excavations in the middle of a field in which cereals were cultivated. These particular corrosion products were attributed to the result of specific interactions between the metallic alloy and residues of agricultural fertilizers and soil amendments, extensively used for decades in this field. This information is significant because of the nature of the changes.