Non-invasive physicochemical investigations of ancient Moroccan Islamic and Jewish parchments

Abstract

Two Islamic parchments dating back to the IXth century along with a third Jewish one whose age is unknown were investigated by means of a completely non-invasive multi-techniques analysis combining all of elemental XRF and structural Raman, ATR-FTIR and FOR spectroscopies. The materials initially used in the preparation of the writing supports were identified; while the Islamic parchments seem to be condensed tannins-pretreated, hydrolysable tannins and lead white have been highlighted in the Jewish one. Collagen gelatinization with molecular helix disorders phenomena have been highlighted in all parchments; degradation products, gypsum and calcium oxalates, have been identified in parchments supports and writing black inks. These latter have been characterized as iron gall types, while all coloring materials have been identified and characterized: Gold, natural minerals and insect extracts. In addition to constituting valuable scientific data prior to future restorations, the obtained results are highly helpful to: i) improving the available codicological data, ii) establishing the traceability of the investigated parchments and iii) enriching the knowledge of ancient writing supports and materials, and highlighting technologies and practices developed by middle ages craftsmen.