Raman Abstracts

Analysis of 16^th Century Qazwini Manuscripts by Raman Microscopy and Remote Laser Raman Microscopy

Robin J.H Clark and Peter J. Gibbs

An in situ, non-intrusive study of a three very rare similar 16^th Century copies of the Qazwini manuscript Aja‰ib al -makhluqat wa ghara‰ib al-mawjudat (the Wonders of Creation and Oddities of Existence) has been performed using Raman microscopy. Seven pigments were identified, of which six were present on each manuscript - vermilion (mercury(II) sulfide), red lead (dilead(II) lead(IV) oxide), lead white (basic lead(II) carbonate), lapis lazuli, carbon black and Indian yellow (magnesium salt of euxanthic acid) and one, verdigris (basic copper(II) ethanoate), on two of the manuscripts: Indian yellow and verdigris have not previously been identified in situ and non-intrusively by this technique on any historical artefact. Each manuscript has been conserved to a different degree and the illuminations on each preserved differently. The degradation of verdigris and lapis lazuli was found to be much worse on one of the manuscripts due at least partly to a particular conservation treatment. The new technique of remote laser Raman (RLR) microscopy was also used to analyze the pigments on one of the manuscripts: this is the first time that RLR microscopy has been applied to archaeometric analysis and the study shows that this technique will make possible the analysis, non-destructively and in situ, of historical artefacts of almost any size.

Raman Microscopy of a 13th Century Illuminated Text

R. J. H. Clark and P. J. Gibbs

An in situ, non-intrusive study of a very rare, early 13^th Century Byzantine / Syriac Gospel lectionary has been performed using Raman microscopy. The research provides unambiguous proof of the nature of a serious conservation problem (the apparent transformation of a white pigment to a black compound) affecting virtually all of the sixty illuminations in this massive volume. Analysis by Raman microscopy proved unambiguously that the white pigment was lead white (basic lead(II) carbonate) and that the black compound was lead(II) sulfide. The possible cause of the deterioration of the white pigment is discussed, and the merits of a proposed treatment to reverse the effect are considered upon. The artist‰s palette was also characterized for the lectionary and, in addition to lead white and lead(II) sulfide, a further five pigments were identified unambiguously: vermilion (mercury(II) sulfide), lapis lazuli, orpiment (arsenic(III) sulfide), realgar (arsenic(II) sulfide) and pararealgar. Pararealgar, a yellow pigment, is a light-induced transformation product of the orange/red pigment realgar and has not previously been identified on any manuscript.

Raman spectroscopic library of natural and synthetic pigments (pre- ~1850 AD)

Ian M. Bell, Robin J.H. Clark and Peter J. Gibbs

To assist in the greatly increasing number of applications of Raman microscopy as a tool for non-intrusive, in situ archaeometric analysis, the Raman spectra of over sixty pigments, both natural and synthetic, known to have been in use before ~1850 AD, have been studied by Raman microscopy. Fifty-six pigments have yielded high quality spectra which have been arranged, by colour, into a spectroscopic library for reference purposes.

Identification of lead(II) sulfide and pararealgar on a 13^th century manuscript by Raman microscopy

R. J. H. Clark and P. J. Gibbs

The in situ non-intrusive chemical analysis by Raman microscopy of a very rare, early 13^th Century, Byzantine / Syriac Gospel lectionary implies that the serious pigment blackening of many hues and affecting most of the illuminations is caused by the degradation of lead white to lead(II) sulfide, and that pararealgar (As₄S₄) - never previously identified on any manuscript - has been used throughout as a deep yellow pigment.

A Non-Destructive, In Situ Study of Ancient Egyptian Faience by Raman Microscopy

R. J. H. Clark and P. J. Gibbs

An in situ, non-destructive study of the coloured glaze on ancient Egyptian faience objects has been performed. The research was undertaken to examine further the effectiveness of Raman microscopy as a tool for archæometric analysis. Initial studies revealed that faience pigmentation could not be analyzed when beneath the glaze but only through cross-sections where the glaze was broken or chipped. Further studies showed that Raman microscopy was unsuitable for the analysis of green, blue and white faience but was extremely effective for the analysis of red and yellow faience. A study of eight red and eight yellow faience fragments, dated to the XVIIIth Dynasty and uncovered at El-Amarna, revealed that all the red fragments were coloured with red ochre or red earth (iron(III) oxide plus clay and silica) and that the colour of the yellow fragments was due to lead antimonate yellow (lead(II) antimonate). 

The Non-Destructive, In Situ, Identification of Cinnabar on Ancient Chinese Manuscripts

R. J. H. Clark, P. J. Gibbs, K.R. Seddon, N. M. Brovenko and Yuri A. Petrosyan

A standard, non-destructive, in situ analytical procedure has been developed to test the theory that cinnabar, mercury(II) sulfide, was the principal component of red inks and pigments on pre-tenth century Chinese manuscripts. Eight manuscript fragments with traces of red ink or pigmentation, and also one textile fragment, were examined by Raman microscopy, Fourier transform near infrared (FT-NIR) Raman spectroscopy, and X-ray fluorescence (XRF) spectroscopy. Mercury(II) sulfide was unambiguously identified on all four paper samples with red calligraphy and on the textile fragment with red pigmentation. Mercury(II) sulfide was not detected on three paper fragments with red legal or punctuation dots or on one paper fragment with a divine image hand-painted in red. The likely identity of the non-cinnabar pigment is madder.

Raman Microscopy: The Identification of Lapis Lazuli on Medieval Pottery Fragments from the South of Italy

R.J.H Clark, M.L Curri and C. Laganara

The technique of Raman microscopy has been used to investigate the pigments used in the glazes of fragments of medieval items of pottery dating back to the second half of the 13th century, which were found buried beneath a church in the abandoned village of Castel Fiorentino, near Foggia, in Southern Italy. The research has led to the first identification of lapis lazuli in a blue pigment pottery glaze; the identification was confirmed for six other shards from the same site. The brown-black pigment in these shards could not be identified.

Raman Microscopy Study of the Pigments on Three Illuminated Mediaeval Latin Manuscripts

L. Burgio, D.A. Ciomartan and R.J.H Clark

The palettes of three Latin manuscripts (MS Lat 8, MS Lat 14 and MS Lat 17) from the collection in the D. M. S. Watson Library at University College London were analysed by Raman microscopy. The pigments vermilion (HgS), kermes (kermesic acid), azurite [2CuCO₃ .Cu(OH)₂], malachite [CuCO₃ . Cu(OH)₃], ivory black (a pigment based on amorphous carbon), white lead [2PbCO₃. Pb(OH)₂] and lead tin yellow type I (Pb₂SnO₄) were identified by Raman microscopy. The Raman spectra of two types of 'mosaic gold,' synthetic tin sulphide (SnS₂), are also given, but were shown not to be present; the illuminations were obtained with gold itself. A second black pigment could not be identified.

Characterization Of Brown-Black and Blue Pigments in Glazed Pottery Fragments from Castel Fiorentino (Foggia, Italy) by Raman Microscopy, X-Ray Powder Diffractometry and X-Ray Photoelectron Spectroscopy

R.J.H Clark, L. Curri, G.S. Henshaw and C. Laganara

Fragments from the archaeological site of Castel Fiorentino (Foggia, Italy) were analysed by Raman microscopy x-ray powder diffractometry and x-ray photoelectron spectroscopy to determine the pigments used in the decoration of this medieval (13-14th century) pottery. Lapis lazuli was identified as the blue pigment and such decoration was established as a characteristic of this pottery class. The brown-black pigment was identified as a manganese oxide, probably MnO₂. The qualitative composition of the glaze was also shown to include tin(IV) oxide (cassiterite) and lead-containing oxides, along with other oxides.

Pigment Identification on Medieval Manuscripts, Paintings and other Artefacts by Raman Microscopy: Applications to the Study of Three German Manuscripts

L. Burgio, D.A. Ciomartan and R.J.H Clark

The identification of the pigments used to illuminate medieval manuscripts, paintings and other artefacts has received a major boostrecently through perceptive studies carried out by Raman microscopy. A brief summary of the background of the technique is given. The results of studies on three illuminated German manuscripts are presented. The pigments vermilion HgS, iron oxide Fe₂O₃, azurite 2CuCO₃.Cu(OH)₂, malachite CuCO₃.Cu(OH)₂, lampblack (essentially carbon), white lead 2PbCO₃.Pb(OH)₂, lead tin yellow type I Pb₂SnO₄, and lazurite Na₈[Al₆Si₆O₂₄]S_n (but only in admixture with Pb₂SnO₄, whereby it forms a green pigment), have been identified on these manuscripts on the basis of Raman microscopy and the results discussed.

Raman Microscopy Applied to the Analysis of the Pigments Used in Two Persian Manuscripts

D.A Ciomartan and R.J.H. Clark

The palettes of two Persian manuscripts Ms Pers 1 (UCL) 'Anatomy of the Body' and Ms Pers 2 (UCL) 'Poetry in Praise' from the collection in the D.M.S. Watson Library at University College London were analyzed by Raman microscopy. The pigments vermilion HgS, red lead Pb₃O₄, lamp black and ivory black (based on amorphous carbon), white lead 2PbCO₃.Pb(OH)₂, orpiment As₂S₃, hydrated ferric hydroxyoxide FeO(OH).nH₂O, and lazurite Na₈[Al₆Si₆O₂₄]S_n were identified.

Synthesis, Structural Characterization and Raman-Spectroscopy of The Inorganic Pigments Lead-Tin Yellow Type-I and Type-II and Lead Antimonate Yellow - Their Identification on Medieval Paintings and Manuscripts

R.J.H Clark, L.Cridland, B.M. Kariuki, K.D.M. Harris and R. Withnall

Lead tin yellow type I (Pb₂SnO₄) and type II (PbSn_1-xSi_xO₃) have each been prepared in a high-temperature furnace, and the preparative conditions defined. The crystal structure of type II has been refined from powder X-ray diffraction data and indicates that the Sn and Si atoms are randomly distributed over the same type of site with Sn/Si ratio approximate to 3/1 (i.e., x approximate to 1/4). The Raman spectra of each form and also that of lead antimonate yellow (Pb₂Sb₂O₇) have been obtained. Raman microscopy is shown: to be an effective technique whereby these inorganic yellow pigments as minute (approximate to 1 mu m) grains may be identified on medieval manuscripts and paintings

Raman Microscopy - Application to the Identification of Pigments on Medieval Manuscripts

R.J.H. Clark

The identification of pigments, in particular the inorganic ones, used to illuminate medieval manuscripts is most effectively carried out by Raman microscopy. The merits of the technique in this context in comparison with others are surveyed; the specificity and sensitivity of a Raman spectrum, the fact that it can be used in situ, and the high spatial resolution (similar to 0.5-1.0 mu m) attainable are all important positive features of the technique. The correct identification of pigments is of great importance in art conservation, and may also assist in the dating of a manuscript. Examples are given of manuscripts which have recently been studied and the pigments identified by Raman microscopy.

Nondestructive Pigment Analysis of Artifacts by Raman Microscopy

S.P. Best, R.J.H. Clark, M.A.M. Daniels and R. Withnall

When integrated with a microscope, Raman spectroscopy provides a uniquely specific and sensitive means of identifying pigment grains of sub-micrometre dimensions in a broad range of artefacts. This article reviews the methodology of Raman microscopy and its application to the study of mediaeval manuscripts.

This UCL Chemistry Webpage was last updated on Saint Veronica's Day (July 12) 2000. This site was compiled by P.J. Gibbs. Should you find a problem with this page, contact the Webmaster.

This page last modified 9 August, 2010