New Insights on the Stradivari “Coristo” Mandolin: A Combined Non-Invasive Spectroscopic Approach

Abstract

In this work, one of the two existing mandolins made by Antonio Stradivari has been investigated for the first time, as a rare exemplar of the lesser-known class of plucked string instruments. The mandolin was studied by non-invasive reflection Fourier transformed infrared (FT-IR) spectroscopy and X-ray fluorescence (XRF) on different areas previously selected by UV-induced fluorescence imaging. The analytical campaign was aimed at (i) identifying the materials used by Stradivari in the finishing of the mandolin, (ii) comparing these materials with those traditionally used in violin making, and (iii) increasing the knowledge of materials and techniques applied by Stradivari in the rare production of plucked string instruments. The combined spectroscopic approach allowed us to hypothesize original materials and finishing procedures similar to those used in violin making: a possible sizing treatment of the wood with protein-based materials and silicates, externally coated with an oil–resin varnish. XRF results were essential to support FT-IR findings and to detect possible iron-based pigments in the finishing layers. Moreover, it permitted us to distinguish original areas from the restored areas, including the purflings on the top plate and the varnished area on the treble side of the mandolin for which the originality was assumed.

Analytical investigations on polychrome artworks from the wooden ceiling of ex-Ospedale San Matteo in Pavia

“…2d). The presence of protein glue and chalk, detected in the areas where there is no longer any drafting and the wood is exposed, could confirm the hypothesis that the wooden boards were prepared with chalk and protein glue [15,16]. IV.…”

Biopolymer Gels as a Cleaning System for Differently Featured Wooden Surfaces

“…X-ray fluorescence (XRF) represents one of the most used elemental analysis in the field of archaeometry and diagnostics of cultural heritage [ 45 , 46 , 47 ], thanks to its quickness, clarity, and non-invasiveness.…”

Preliminary Cleaning Approach with Alginate and Konjac Glucomannan Polysaccharide Gel for the Surfaces of East Asian and Western String Musical Instruments

“…For EAM, signals of K, Ca, Ti, Cr, Mn, and Zn and a weak signal of Fe (Kα = 6.43 keV) were detected. Detected elements, K, Ca, Ti, Cr, Mn, and Zn, on both mock-ups derive mainly from the wood [56,57], although K and Ca increase in count in WM, probably due to the presence of the ground and varnish layers [42,58]. Regarding On the EAM areas cleaned by SA gel two and three times (SA_2 and SA_3), it was observed that the related L * values (35.2 ± 1.0 and 35.7 ± 2.2, respectively) are close to the L * value of the area without the soiling mixture (36.0 ± 0.6), implying a good removal.…”

“…For EAM, signals of K, Ca, Ti, Cr, Mn, and Zn and a weak signal of Fe (Kα = 6.43 keV) were detected. Detected elements, K, Ca, Ti, Cr, Mn, and Zn, on both mock-ups derive mainly from the wood [56,57], although K and Ca increase in count in WM, probably due to the presence of the ground and varnish layers [42,58]. Regarding the soiling mixture applied on WM and EAM, Si (Kα = 1.74 keV), K, Ca, and Fe were the principal elements detected: Ca (kaolin, cement), Fe (cement, burnt sienna pigment), K (peat moss, kaolin), Si (kaolin, silica, cement).…”