Integration of μ-XRF, and u-Raman techniques to study ancient Islamic manuscripts

Systematic characterizations of inks used in three ancient Arabic manuscripts were performed using energy dispersive X-ray fluorescence (EDXRF) and RAMAN spectroscopy. Spatially resolved element distributions obtained by area scans in addition to spot analysis provided detailed information about the manuscripts. RAMAN spectroscopy, on the other hand provided decisive information about the compounds used in various color pigments. Different compounds were found in the red ink in each manuscript: HgS (cinnabar) in one manuscript, red lead Pb304 (minium) in the second, and a mixture of the two in the third manuscript. The green pigment was Cu based and it is probably malachite (Cu2CO3(OH)2), while the black ink pigment in the three manuscripts is iron gall (Fe2SO4 plus gallottanic acid). Analytical results and the context of the manuscripts were used to extract information about the authenticity and origin of the manuscripts. For example, the use of cinnabar as a red ink pigment found in the third manuscript reveals that this manuscript attributed to Al-Gazali (11th century) is probably a copy from a later period, because cinnabar was first introduced in the 16th century.