On‐site Raman and XRF analysis of Japanese/Chinese bronze/brass patina – the search for specific Raman signatures

Abstract

The assignment of Asian bronzes and brasses is difficult because the copies of ancient pieces have been made a long time ago in different countries. A selection of 30 Japanese and/or Chinese bronzes/brasses are studied on‐site in the storage and exhibition rooms of the Cernuschi Museum, in Paris, using portable Raman and X‐ray fluorescence spectrometers. Attempts are made to identify specific Raman signatures of the patina to detect similarity in a nondestructive procedure. X‐ray fluorescence measurements allow an identification of two brass artefacts and different types of bronze, including lead‐rich and mixed lead–tin–zinc‐rich compositions. The following phases are identified: CuO, Cu2O, Cu2S, tin oxides, ZnO, Cu3(OH)4SO4, Cu4(OH)6SO4, 3PbOPbSO4 H2O, PbSO4/PbO, Pb(AsO4)3Cl, HgO/HgS. Relics of the mould, retained as concretions at the artefact surface are also identified: TiO2, SiO2, and different soda(−lime) glasses. Patina with very similar colour and habit may have different Raman signatures. This study offers tools to classify the artefacts in a noninvasive way. Copyright © 2011 John Wiley & Sons, Ltd.

In situ synthesis of gold nanoparticles (AuNPs) in butterfly wings for surface enhanced Raman spectroscopy (SERS)

“…[1][2][3][4][5][6][7][8][9][10] Recently, SERS have drawn more and more attention and made great progress, especially with the rapid development of nanotechnology and nanomaterials. [1][2][3][4][5][6][7][8][9][10] Recently, SERS have drawn more and more attention and made great progress, especially with the rapid development of nanotechnology and nanomaterials.…”

Study of corrosion in archaeological gilded irons by Raman imaging and a coupled scanning electron microscope–Raman system

“…On the other hand, Raman spectroscopy, owing to its sensitivity, versatility, portability and non-destructive features, is becoming the reference analytical technique for molecular characterization of cultural heritage items [13][14][15]. Depending on the requirements, Raman spectroscopy can also be replaced or accompanied by additional molecular instrumentation, such as Fourier transform infrared spectroscopy (FTIR) [16,17] and fibre-optic reflectance spectroscopy (FORS) [18,19].…”

Lacquerware Pigment Identification with Fixed and Mobile Raman Microspectrometers: A Potential Technique to Differentiate Original/Fake Artworks

“…Phase transformation under the laser beam is not excluded, although no visible changes were detected. The weak 474 cm −1 peak ( Figure 5, center spectrum) may correspond to CuS [17], another traditional red pigment, and/or to associated sulfide impurities of the realgar/orpiment mixture. The impossibility to record a spectrum below 200 cm makes it difficult to reliably assign these low intensity peaks.…”

“…Pigments and specific mixtures by which sometimes they were commercialized can be used to trace given periods of production. Therefore identification of specific pigments in artwork can be used for dating purposes, as was already demonstrated for paintings, glass, ceramic or enameled metal objects [1,3,[5][6][7][8][9][10][11][12][13][14][15][16][17][18]. Their presence of certain pigments may indicate a restoration, later embellishment or identify a fake or a modern replica.…”

“…Portable IR instrument determines the media and 785 nm Raman instrument identifies only a limited number of the pigments identified at the laboratory with fixed instruments. Previous lacquerware studies dealt with archaeological artifacts and with Japanese urushi, [16][17][18] th century artifacts [21][22][23][24][25][26][27][28][29][30], mainly using Pyrolysis Gas Chromatography and Mass Spectrometry (Py-GC/MS) but did not concern the pigment palette identification. FT-IR spectroscopy was also used on powdered samples in KBr pellets or specially prepared films [26][27][28][29].…”