Archeometrical Study of the Middle Ages artefacts found near Mons, Belgium.

It is often difficult to determine the precise date of manufacture of an ancient steel artefact simply based on metallurgical analysis. Sometimes, other objects present at the excavation site, such as coins or ceramics, can help to determine the precise date. Sometimes, however, it's also necessary to determine how the object was manufactured and to carry out historical research into the activities of the region in which the object was found.

An artefact from the Late Middle Ages was studied to determine its fabrication date: the statue of a monkey (a barbary macaque), named “Grand'Garde Monkey“, which is located on the facade of the town hall in Mons, Belgium. A comparison with a steel bar coming from a window of the basement of the Castle of Boussu (located 10 km from Mons) has been undertaken since historical sources certify that the basement was made in the 16^th century.

Their chemical composition was analyzed with portable X-ray fluorescence equipment; their mechanical properties were evaluated by macrohardness. The samples were further characterized by X-ray diffraction (XRD), optical microscopy (OM), and scanning electron microscopy (SEM) coupled with X-ray energy dispersion spectrometry (EDS). In addition, a comparison was made with samples of bloomery steel made in our laboratory.

The results show that the two Middle Ages artefacts are made of low-carbon steel, with slag inclusions in their microstructure, and that they are thus made of bloomery steel. Their age is then before the 18^th century. From the historical analysis of the bloomery process in the region of Mons and with the help of other artefacts found with the steel bar, they could be processed in the 15^th-16^th century.