A multi-technique study on materials used for the painting "Cristo alla Colonna" by Luigi Bria (private collection, Cosenza, Italy) was carried out for the first time during the restoration plan. Pigments, binder media and raw materials used for the application of ground and priming layers were studied using optical (OM) and electronic microscopy equipped with energy dispersive spectroscopy qualitative microanalysis (SEM-EDS), infrared spectroscopy (FTIR) and gas chromatography coupled with mass spectrometry (GC/MS). The goal of this study was to characterize this canvas and to set up a scientific aid and guide for its restoration, taking into account the, severe damage not exclusively due to natural decay processes. Our data can provide information about historical and stylistic background as well as advises for correct planning of the cleaning procedures. Riassunto - II dipinto su tela "Cristo alla Colonna", opera di Luigi Bria (collezione privata, Cosenza, Italia), \ue8 stato sottoposto, durante le fasi di restauro, per la prima volta ad indagine strumentale tramite varie tecniche analitiche. I pigmenti, i leganti ed altri materiali utilizzati per la sua realizzazione sono stati analizzati tramite microscopia ottica (OM), microscopia elettronica e microanalisi tramite spettrometria a dispersione di energia (SEM-EDS), spettroscopia infrarossa (FTIR) e gascromatografia accoppiata spettrometria di massa (CG/MS). Lo scopo del lavoro \ue8 stato quello di offrire una caratterizzazione dell'opera pittorica, nonch\ue9 fornire un supporto scientifico ad un un corretto intervento di restauro su un'opera fortemente degradata. I risultati hanno permesso di fornire informazioni di natura storico-artistico nonch\ue9 informazioni utili ad un corretto intervento di pulitura della tela oggetto di questo studio

A. Casoli

A.M. De Francesco

D. Barca

D. Miriello

G. Nava

G.M. Crisci

M.F. La Russa

S.A. Ruffolo

V. Comite

AIR Universita degli studi di Milano

ABStrACt - A multi-technique study on materials
used for the painting “Cristo alla Colonna” by luigi
Bria (private collection, Cosenza, italy) was carried out
for the first time during the restoration plan. Pigments,
binder media and raw materials used for the application
of ground and priming layers were studied using
optical (oM) and electronic microscopy equipped with
energy dispersive spectroscopy qualitative
microanalysis (SEM-EDS), infrared spectroscopy
(ftir) and gas chromatography coupled with mass
spectrometry (GC/MS). the goal of this study was to
characterize  this canvas and to set up a scientific aid
and guide for its restoration, taking into account the,
severe damage not exclusively due to natural decay
processes. our data can provide information about
historical and stylistic background  as well as advises
for correct planning of the cleaning procedures.
riASSunto - il dipinto su tela “Cristo alla Colonna”,
opera di luigi Bria (collezione privata, Cosenza, ita-
lia), è stato sottoposto, durante le fasi di restauro, per
la prima volta ad indagine strumentale tramite varie
tecniche analitiche. i pigmenti, i leganti ed altri mate-
riali utilizzati per la sua realizzazione sono stati ana-
lizzati tramite microscopia ottica (oM), microscopia
elettronica e microanalisi tramite spettrometria a di-
spersione di energia (SEM-EDS), spettroscopia infra-
rossa (ftir) e gascromatografia accoppiata
spettrometria di massa (CG/MS). lo scopo del lavoro
è stato quello di offrire una caratterizzazione dell’o-
pera pittorica, nonché fornire un supporto scientifico
ad un un corretto intervento di restauro su un’opera
fortemente degradata. i risultati hanno permesso di
fornire informazioni di natura storico-artistico nonché
informazioni utili ad un corretto intervento di pulitura
della tela oggetto di questo studio. 
KEy worDS: Italian canvas; multi-technique
approach; restoration.
introDuCtion
Physical, chemical and structural investigations
of paintings, essential components of worldwide
cultural heritage, represent essential tools for their
characterization. the resulting scientific information
are basic for highlighting the various stages of the
degradation processes as well. they can be also
useful to suggest appropriate restoration
procedures and to plan conservation projects
(Mora et al.,1984; Botticelli, 1993; Henderson,
2000; Ciliberto and Spoto, 2000; Matteini and
Moles, 2002a; Matteini and Moles, 2002b). for
the first time multi-technique investigations were
PerIodICo di MIneralogIa
established in 1930
Period. Mineral. (2010), Special Issue, 71-79 doi: 10.2451/2010PM0022
http://go.to/permin
An International Journal of
MINERALOGY, CRYSTALLOGRAPHY, GEOCHEMISTRY,
ORE DEPOSITS, PETROLOGY, VOLCANOLOGY
and applied topics on Environment, Archeometry and Cultural Heritage
Mineralogical, petrographic and chemical analyses for the study of the
canvas “Cristo alla Colonna“ from Cosenza, Italy: a case study
SilvEStro A. ruffolo1, MAuro f. lA ruSSA1*, DonAtEllA BArCA1, AntonEllA CASoli1, vAlEriA CoMitE1,
GiAnluCA nAvA3, Gino M. CriSCi1, AnnA M. DE frAnCESCo1 and DoMEniCo MiriEllo1
1Dipartimento di Scienze della terra, università della Calabria, via Pietro Bucci, Arcavacata di rende, italy
2Dipartimento di Chimica Generale ed inorganica, università di Parma, v.le usberti 17/A, 43100 Parma, italy
3laboratorio “nova Ars restaurandi”, Corso telesio, 69, Cosenza, italy
Submitted, September 2010 - Accepted, November 2010
*Corresponding author, E-mail: mlarussa@unical.it
ruffolo:periodico  30/11/2010  15:34  Pagina 71
72 S.A. ruffolo, M.f. lA ruSSA, D. BArCA, A. CASoli, v. CoMitE, G. nAvA et al.
carried out on small fragments sampled in the
painted on the canvas named “Cristo alla
Colonna” (fig. 1), preserved in the private
collection located in Cosenza (southern italy).
the author, probably neapolitan seems to be
“luigi Bria” and the date reported on the painting
is “8 September 1849, naples”. “Cristo alla
Colonna” canvas, shows the figure of Jesus with
crossed hands and only thong tied to the right
side. rope, that usually accompanies such type
of iconography, is not present. Alongside the
scarlet cloak lying on the ground, there are
Christian symbols of the Passion (whip and cane).
this painting has never studied before; it can
be considered an important artwork because
luigi Bria represent an important artist, studied
by critics despite at the state of art they are only
fragmentary information on him. (Spinosa, 1997) 
fig. 1 - the canvas painting “Cristo alla Colonna” (45x63 cm); the sample points are also reported.
ruffolo:periodico  30/11/2010  15:34  Pagina 72
we have undertaken a characterization study of
some representative samples coming from various
zones of the painting by combined mineralogical,
petrographic, chemical and spectroscopic
techniques, in order to obtain useful information
about the painting technique, to ascertain the type
and the extent of the degradation processes which
affected the canvas and to detect the materials
used in previous restoration attempts. Moreover,
this research would offer a guide for an adequate
restoration project of this artefact; the canvas
showed an advanced state of deterioration that has
made it necessary a marked recovery intervention.
At an first visual inspection the canvas appeared
to be damaged in both the protective film, which
was uneven and oxidized, and in the pictorial
layer, that was characterized by exfoliation,
fragmentation, vacancies and by the typical
craquelure structure.
SAMPlE DESCriPtion AnD MEtHoDS
five samples, mostly smaller than 5 mm, were
collected from different scenes and decorative
elements (tABlE 1 and fig. 2). Sampling was
conducted following the restoration procedures
of  and according to a principle of minimum
invasiveness, i.e. taking samples from the
margins of existing lacunae.
Preliminary study has consisted in optical
microscopy (oM) observations of the samples,
prepared on purpose as cross-sections, by means
of a Zeiss Axiolab polarizing microscope equipped
with transmitted/reflected light apparatus. this
technique has allowed us to recognize the painting
techniques and the textural relationships between
the various microstratigraphical units across the
painting sections. A first identification of the binder
types and their microstructural features has been
made as well. Morphological observation and
elemental characterization of samples were
performed using a fEi Quanta 200f (Philips)
scanning electronic microscope (SEM), coupled
with an energy dispersive X-ray spectrometer
(EDS). All the SEM-EDS analyses were carried
out with an acceleration voltage of 20 kv and
under low vacuum conditions (10–5 mbar pressure).
A fourier transform infrared spectrometer (ftir,
Perkin–Elmer Spectrum 100 instrument) has been
used to obtain molecular information on binders.
ir spectra were recorded on powder pellets in
Atr mode in the range of 4000-650 cm−1, with
a resolution of 4 cm−1. organic binder media
have been analysed by gas chromato graphic
analyses coupled with mass spectrometry (GC/
MS), due to its high sensitivity in determining
the nature of organic substances (e.g. drying oils
and proteinaceous materials). A gas chromato -
graph (6890n) coupled with a 5973 mass selective
detector (both from Agilent technologies) and a
single-quadruple mass spectrometer was employed. 
rESultS AnD DiSCuSSion
OM, SEM-EDS
under the optical microscopy and on reflected
light, all samples show different stratigraphic
typologies. 
Sample A1 is constituted by a flesh coloured
painted layer. Elemental analysis reveals an high
lead content due to the presence of white lead,
likely composed of hydrocerussite
[2PbCo3·Pb(oH)2] (fig. 3a)
this pigment is synthetic and used up to the
nineteenth century; afterwards, because of its
high toxicity, it was replaced by zinc white and
in the twentieth century by “titanium white”
(Matteini and Moles, 2002a). EDS microanalyses
have also revealed the presence of antimony (Sb)
and iron (fe) in small amounts, probably related
to the yellow pigment called “Naples Yellow”
which is mainly formed by lead antimonate
[Pb3(Sbo4)2]. furthermore, the presence of traces
of sulphur (S) and mercury (Hg) in the spectrum
can be related to the presence of cinnabar (HgS),
a well known red pigment. All these chemical
component are coherent with the formulation of
73Mineralogical, petrographic and chemical analyses for the study of the canvas “Cristo alla ...
ruffolo:periodico  30/11/2010  15:34  Pagina 73
the flesh colouring , normally made of a mixture
of white, with small amounts of yellow and red.
Sample A2 consists of a white priming covered
by a green pigmented layer. EDS spectra show
lead in the white preparation, whereas in the
green layer several elements have been detected,
i.e. fe, Si, Al, K, Ca together with Pb (fig. 3b).
Both morphological observations showed a clay
platelet mineral (fig. 4a) and EDS qualitative
microanalysis can indicate the presence of clay
minerals, the so-called “green earth” (Matteini
and Moles, 2002a).
Specimen A3 is composed of two layers, as
shown by image analysis obtained from
backscattered scanning electron microscopy
(BSE-SEM) given in fig. 4b. Qualitative EDS
analysis has highlighted the presence of different
pigments (fig. 3c). lead was used for the white
74 S.A. ruffolo, M.f. lA ruSSA, D. BArCA, A. CASoli, v. CoMitE, G. nAvA et al.
fig. 2 - Details of sampling points shown in fig. 1.
Sample description
A1 Christ’s left bicep. flesh colour
A2
Base of the column, where Christ
is rested. Green
A3 Base under left foot. Dark brown
A4
Base, left side of the painting.
Dark brown
A5
Background, left side of painting.
Black
tABlE 1
List and description of samples.
ruffolo:periodico  30/11/2010  15:34  Pagina 74
75Mineralogical, petrographic and chemical analyses for the study of the canvas “Cristo alla ...
fig. 3 - Selected EDS spectra of: a) sample A1, b) painted layer in sample A2; c) selected area in painted layer in sample A3;
d) selected area in painted layer in sample A3.
fig. 4 - a) BSE-SEM image of a detail of painted layer in A2 sample, the arrow indicates a clay mineral habitus; b, d) BSE-
SEM micrographs of samples A3 and A4; c, e) Cross section images acquired by optical microscope, visible reflected light
mode, of sample A4 and A5.
ruffolo:periodico  30/11/2010  15:34  Pagina 75
preparation. in painted layer, elemental analysis
(Si, fe, Mg, K) and chromatic evaluation are
coherent with the presence of “green earth” and
other clay minerals, “verderame”
[Cu(CH3Coo)2·2Cu(oH)2]
or malachite
[CuCo3·Cu(oH)2]
the occurrence of the latter two mineral
components can be suggested by the presence of
copper in the EDS spectrum (fig. 3d). A copper
acetate was probably used for brighten up the
green pigments (Matteini and Moles, 2002a).
the presence of Sb can be due to the naples
yellow pigment (fig 3c).
Cross-section and BSE-SEM micrographs of
sample A4 has pointed out three different layers
(fig. 4c, d): a white ground with a maximum
thickness of about 450 µm; a brownish painted
layer and a translucent reddish thick layer (40
µm). Micro analytical data indicate the presence
of lead in the white preparation and calcium
sulphate on the upper surface of the sample,
coming probably from a previous restoration
attempts. 
Sample A5 shows four different layers (fig.
4e), e.g. an homogeneous superficial layer brown
in colour, a layer with a lighter colour, a third
layer constituted by a mixture of a dark
groundmass and grains with different size and
shape. finally it is visible a preparation layer.
Microanalytical data show similar  composition
to A4 sample.
FTIR spectroscopy
ftir investigations, carried out on different
painting layers, gave further information on the
original binding materials and on inorganic and
organic materials which form the samples. All
spectra collected show typical features lipidic
matter. A representative ftir spectrum (sample
A4) is reported in fig. 5. it is evident a carboxylic
ester (attributable to oils) due to the band at 1764
cm-1 (C=o) and the peak centred at 1163 cm-1
assigned to stretching of C-o-C (favaro et al., in
press). Bands at 1463 cm-1 represent the bending
of CH2 groups. furthermore spectra revealed
various abundances of calcium oxalate
76 S.A. ruffolo, M.f. lA ruSSA, D. BArCA, A. CASoli, v. CoMitE, G. nAvA et al.
fig. 5 - ftir spectrum of sample A5.
ruffolo:periodico  30/11/2010  15:34  Pagina 76
monohydrate (CaC2o4·H2o), commonly called
whewellite, highlighted by bands at 1640, 1324,
786 and 680 cm-1 (rampazzi et al. 2004).
Calcium carbonate (CaCo3) vibrations are
peaked at 1409, 705 and 611 cm–1, while silicates
were identified by signal at 1032 cm–1. finally in
samples A3, A4 and A5 it is evident the lead
carbonate bands centred at 1438 e 1419 cm-1
(Cotte et al., 2007).
GC/MS analysis 
Painted layer of sample A5 were analysed by
GC-MS technique as well, because it ca give
additional information on organic compounds of
binder media. Chromatogram of the lipidic
fraction shows the presence of dicarboxylic acids
(CC8 - suberic acid, CC9 - azelaic acid) and
monocarboxylic acids both saturated (C16:0 -
palmitic acid, C18:0 - stearic acid) and
unsaturated (C18:1 - oleic acid) (fig. 6a).
the presence and the amount of azelaic acid,
whose formation is due to the oxidation of
unsaturated acids, and oleic acid suggests that
the observed lipidic fraction can be attributed to
siccative oil. Concentration ratios between
azelaic /palmitic acid (0.82) and palmitic /stearic
acid (1.33) revealed the presence of linseed oil.
(Casoli et al., 1999).
GC/MS data have demostrated the presence of
proteinaceous matter, not been revealed by ftir
analysis. Chromatogram of amino acids is shown
in fig. 6b. to identify its real nature, the amount
of 8 amino acids were considered (alanine,
glycine, leucine, proline, hydroxyproline,
aspartic acid, glutamic acid, phenylalanine). A
comparison between results and a suitable set of
reference proteinaceous material has been
conducted according to the multivariate
statistical analysis by means of principal
component analysis method (PCA), which
provides a rapid classification of unknown
samples (Casoli et al.,1995, 1996, 2001). Main
components are a linear combinations of original
variables (the 8 amino acids considered). the use
of PCA, whose result is shown in fig. 7,
classifies the sample in the animal glue group.
ConCluSionS
Multianalytical strategy allowed us to fully
characterize both inorganic and organic
components of the painting materials used in
“Cristo alla Colonna”. the painting technique
77Mineralogical, petrographic and chemical analyses for the study of the canvas “Cristo alla ...
fig. 6 - a) CG chromatogram of lipidic and b) proteinaceous
fractions extracted from sample A5.
ruffolo:periodico  30/11/2010  15:34  Pagina 77
emerging from mineralogical, petrographic and
chemical data is consistent with the period in
which it was framed, i.e. mid-nineteenth century.
in particular GC/MS analyses suggest the
presence of animal glue and linseed oil as
binders. this latter result could to be useful for
suggesting the conservation procedures,
especially for the cleaning method to be adopted.
A proper cleaning action allowed to recover
iconographic details that were completely
obliterated by alteration of the painting surface.
ACKnowlEDGEMEntS
the authors gratefully acknowledge the editor in
chief, A. Gianfagna, the co-editors A.M. De francesco
and G. Saviano. furthermore we would like to thank
the anonymous reviewers for their constructive
comments, which significantly improved the quality
of this paper.
rEfErEnCES
BottiCElli G. (1993 ) - Metodologia di Restauro delle
Pitture Murali, Centro di Firenze.
78 S.A. ruffolo, M.f. lA ruSSA, D. BArCA, A. CASoli, v. CoMitE, G. nAvA et al.
fig. 7 - PCA chart. Classification of reference samples (animal glue, egg and milk) and sample A5 on the basis of their amino
acidic composition.
Animal glue
egg
milk
ruffolo:periodico  30/11/2010  15:34  Pagina 78
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Mineralogical, petrographic and chemical analyses for the study of the canvas &quot;Cristo alla Colonna&quot; from Cosenza, Italy : a case study

A multi-technique study on materials
used for the painting “Cristo alla Colonna” by luigi
Bria (private collection, Cosenza, italy) was carried out
for the first time during the restoration plan. Pigments,
binder media and raw materials used for the application
of ground and priming layers were studied using
optical (oM) and electronic microscopy equipped with
energy dispersive spectroscopy qualitative
microanalysis (SEM-EDS), infrared spectroscopy
(ftir) and gas chromatography coupled with mass
spectrometry (GC/MS). the goal of this study was to
characterize this canvas and to set up a scientific aid
and guide for its restoration, taking into account the,
severe damage not exclusively due to natural decay
processes. our data can provide information about
historical and stylistic background as well as advises
for correct planning of the cleaning procedures

Silvestro A. Ruffolo

Mauro F. La Russa

Donatella Barca

CASOLI, Antonella

Valeria Comite

Gianluca Nava

Gino M. Crisci

Anna M. De Francesco

Domenico Miriello

Archivio istituzionale della Ricerca -  Università degli Studi di Parma