The Book of Kells: A non-invasive MOLAB investigation by complementary spectroscopic techniques

• Published in: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Vol. 115; pp. 330 - 336
• Main Authors: Doherty, B., Daveri, A., Clementi, C., Romani, A., Bioletti, S., Brunetti, B., Sgamellotti, A., Miliani, C.
• Format: Journal Article
• Language: English
• Published: England Elsevier B.V 01-11-2013
• Subjects: Anhydrite; Book of Kells; Calcium Sulfate - chemistry; In situ investigation; Laboratories; Manuscripts as Topic; MOLAB; Orchil dye; Portable instrumentation; Spectrometry, Fluorescence; Spectrometry, X-Ray Emission; Spectrophotometry, Infrared; Spectrophotometry, Ultraviolet; Spectrum Analysis - methods; MOLAB; In situ investigation; Anhydrite; Orchil dye; Book of Kells; Portable instrumentation
• ISSN: 1386-1425; 1873-3557
• DOI: 10.1016/j.saa.2013.06.020

•The Book of Kells is assessed by non-invasive in situ portable spectroscopy.•Complementary techniques highlight the intentional use of anhydrite.•Rare identification of the organic lichen dye, orchil in a manuscript.•Alteration of organic black giving rise to calcium carboxylate and calcium oxalate.
This paper highlights the efficacy of non-invasive portable spectroscopy for assessing the execution technique and constituent materials in one of the most important medieval manuscripts, the Book of Kells. An aimed campaign of in situ measurements by the MObile LABoratory (MOLAB) has analyzed its elemental composition and vibrational and electronic molecular properties. The ample analytical toolbox has afforded complementary diagnostic information of the pigment palette permitting the characterization of both inorganic and organic materials as pigments and dyes in the white, purple, blue, red, orange, green and black areas. In particular, the novel widespread use of calcinated gypsum (anhydrite) as both a white pigment and in correlation to the organic dyes in this manuscript has been noted. The non-invasive identification of the organic dye orchil is significant considering its rare non invasive detection in medieval manuscripts. Finally the occurrence of particular alterations of the organic black areas giving rise to calcium carboxylate and calcium oxalate has been specifically highlighted. Importantly, this work elaborates complex aspects of the employed painting materials which have given rise to numerous significant points of interest for a more elaborate understanding of this Irish treasure.