iron-gall ink

Evidence

"One line scan corresponds to the analysis of the support whereas the other five analyses correspond to different ink spots on the same manuscript: the main text and the signatures of Yefet b. David, Ephraim b. Shemarya, Yaacov b. Mevasser and Shmuel ha-Cohen b. Avtalyon. ... iron (Fe) at 6.4 keV for Kα and 7 keV for Kβ."

Remarks

The XRF spectra for T-S 8J4.3 fol. 1r show peaks for iron (Fe), potassium (K), calcium (Ca), and chlorine (Cl). The fingerprint model relies on ratios of satellite impurities (Cu, Zn, Mn, Pb) normalized to iron to differentiate vitriolic iron-gall inks (p. 62). The analysis of this specific manuscript included signatures from prominent 11th-century figures like Ephraim b. Shemarya (p. 61).