Study Of A 12th -Century Fragment Of Hauberk With Black Magnetite Patina

This is the study of a fragment of hauberk from an excavation carried out on a plot of land next to the church of S. Vicente in Vitoria-Gasteiz (Álava, Basque Country, Spain). The steel rings have a patina of matt black artificial magnetite. This patina with evident decorative effect, while protective of the corrosion and the rust, was obtained artificially to high temperature as it is deduced of the microstructure resulting from the steel of the rings. The research was carried out by Scanning Electron Microscopy (M.E.B.) and X-ray diffraction.