Until recently, it was assumed that the ink used for writing in ancient Egypt was primarily carbon-based, at least until the 4th to the 5th century CE. However, a new study shows that black carbon ink on ancient Egyptian papyri from different time periods and geographical regions contained copper.
A cross-disciplinary team at the University of Copenhagen, Denmark discovered in a new study published on Friday in Scientific Reports, traces of copper, a previously-undocumented compound in the pigments, suggesting they were a by-product of sulphurous ore smelting.
The inks were investigated using synchrotron-based micro x-ray fluorescence (XRF) and micro x-ray absorption near-edge structure spectroscopy (XANES) at the European Synchrotron Radiation Facility (ESRF).
Micro XRF analyses of two papyrus fragments from the ancient town of Herculaneum have shown that lead compounds were already added to black ink in the 1st century CE, thereby modifying our knowledge of ink manufacture in antiquity.
The composition of the copper-containing carbon inks showed no significant differences that could be related to time periods or the geographical locations. This renders it probable that the same technology for ink production was used throughout Egypt for a period spanning at least 300 years. It is argued that the black pigment material (soot) of these inks was obtained as by-products of technical metallurgy, according to the study.
The copper can be correlated with the following three main components: cuprite, azurite and malachite.
The studied fragments form parts of larger manuscripts belonging to the Papyrus Carlsberg Collection, University of Copenhagen, and can be divided into two groups: the first comes from southern Egypt and consists of the private papers of an Egyptian soldier, Horus, who was stationed at the military camp of Pathyris, located at modern Gebelein, some 30 km south of Luxor. The second group derives from the only large-scale institutional library to survive from ancient Egypt, the Tebtunis temple library.