Virtuous colours for Mary. Identification of lapis lazuli, smalt and cochineal in the Andean colonial image of Our Lady of Copacabana (Bolivia)

Abstract

The image of Our Lady of Copacabana, a gilded polychrome sculpture carved in maguey wood in 1583, is one of the most important devotions in the Americas. In former research, we have identified the use of gypsum, Armenian bole, cerussite and atacamite in its polychromy. In this study, a red sample taken from the Virgin's tunic and a blue sample extracted from the cloak have been analysed with the aim to identify both pigments and offer insights into the painting technique. Analysis by micro-Raman spectroscopy complemented with scanning electron microscopy-energy dispersive spectroscopy and high-performance liquid chromatography allowed the identification of carmine lake in the red sample. Analysis by micro-Raman spectroscopy of the surface of the blue sample and its cross section showed the presence of smalt-the blue-glass pigment-over a cerussite layer, bathed by a very thin ultramarine layer-from a probable native origin-following a pictorial tradition that would last even until the eighteenth century. This is the first time that lapis lazuli has been scientifically identified in a Spanish American colonial painted layer.This article is part of the themed issue 'Raman spectroscopy in art and archaeology'.

Characterization of pigments and binders in a mural painting from the Andean church of San Andrés de Pachama (northernmost of Chile)

“…Acid hydrolysis of the red microsample to obtain the dye and further analysis by C 18 HPLC-DAD indicated a peak at 14.25 min in the chromatogram ( Fig. 10) whose UV spectrum showed bands at 275 and 495 nm, which matched those of the carminic acid reference and literature data [6].…”

“…Red earths containing hematite have been identified as pigments in Andean paintings [4,5,[35][36][37] and sculptures [7]. Recently, in our investigations on the polychrome of the sculpture of Our Lady of Copacabana in Bolivia we have reported the use of a red bole containing hematite in the gilding of the sculpture [6]. To our knowledge this is the first time that a mixture of hematite with orpiment is used as an orange paint in colonial art.…”

“…It has not been produced in the Viceroyalty of Peru so it had to be imported from Europe [27]. As part of our investigations on the chromatic palette of colonial artworks, we have identified smalt in various Andean paintings from the seventeenth and eighteenth centuries [23] and in the Virgin's cloak of the gilded polychrome sculpture of Our Lady of Copacabana in Bolivia [6]. This is the first report of smalt in a wall painting of an Andean church.…”

“…A confocal aperture of 50-μm slit was used and 80 expositions of 2 s each were averaged. HPLC-DAD analysis was performed on a Gilson 506C chromatograph as described in [6]. Sample PCH10 and a carmine lake standard (Carmine Naccarat 42100, Kremer) were hydrolysed in acidic methanol as reported previously [7].…”

“…The Raman spectrum (not shown) of the surface of sample PCH10 revealed a high fluorescence background and weak bands at 1110, 1245, 1310, 1495, and 1567 cm −1 , which suggested the use of carmine, a red lake pigment prepared from carminic acid, the main anthraquinone glucoside in the insect Dactylopius coccus Costa [6,56]. Acid hydrolysis of the red microsample to obtain the dye and further analysis by C 18 HPLC-DAD indicated a peak at 14.25 min in the chromatogram ( Fig.…”