Non Destructive Analysis of Dyes and Ceramics

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1 Non Destructive Analysis of Dyes and Ceramics EnSpectr R532 helps artworks restoration process with rapid in-situ analysis of pigments and materials Raman spectroscopy is a high-power instrument for noninvasive analysis of artworks. The knowledge of pigments from a painting can reveal a lot about its authenticity: each painter and each epoch used to works with different pigments. For instance, the most typical dyes of ancient times are mineral ones: mineral blue (azurite), lapis lazuli as an example. These two minerals like almost any other ones can be easily distinguished by EnSpectr R532. Besides paintings, Raman can perfectly measure spectrum of ceramics. An acquired spectrum tells about the type of clay used, pigments appearing in images on the surface of a bowl. These facts as well help identify authenticity, age, authors of artworks. Raman spectroscopy is a useful tool tor archaeometric analysis of ancient pottery. In combination with other methods of nondestructive analysis of art paintings and clay products, Raman spectroscopy is exceedingly useful, though, just as any known method, it is not a panacea and also has some limitations. In some cases satisfactory results cannot be achieved due to a high luminescence emitted by material. This is a fundamental problem which can hardly be solved with lasers of longer (785 nm) excitation wavelength. Another problem is that some dyes simply have a very weak Raman signal. EnSpectr R532 for Arts & Restoration EnSpectr R532 was tested in storerooms of National Tretyakovskaya Gallery, All-Russian Artistic Scientific and Restoration Center named after academician I.E. Grabar and in Moscow Museum of Modern Art for identification of pigments from art paintings. The instruments demonstrated splendid performance and successfully identified chemical composition of most Ramansensitive dyes and materials.

2 In Restoration Center named after I.E. Grabar EnSpectr R532 analyzed very small particles of paintings (that was possible due to a restoration process over some artworks). While examining such a particle the instrument scanned the very edge of it and showed different layers and pigments and corresponding spectra. In collaboration with University of Lisbon, Portugal, we experimented with local ceramics. Experimenting with a piece of a ceramics covered with glaze we acquired spectra of painting s pigment blue glaze (besides we had an opportunity to compare it with a pure dye spectrum measured from powdered dye) and from ceramic material. Old ceramic tiles from building facade, Lisbon Similarly to the painting particle, we measured a single split on the piece and acquired intensive Raman peaks. EnSpectr R532 Advantages: High spatial resolution of 1 µm (Raman Microscope) or 20 µm (R532 on a sample stage is applied) allows measuring under 1 µg microprobes from artworks being under restoration. The spectrum can be acquired from the edge of a split discovering different substances on each layer. Discovering the essence: in National Tretyakovskaya Gallery we measured spectra of paintings directly from artworks; good results were also obtained through a layer of lacquer for some masterpieces, and from tiny splits on artworks including clay products. Rapid analysis: time per measurement < 3 seconds. Superb delicacy and sensitivity: even with laser power of 12 mw and less (which is crucial in case of inspecting dark paints) EnSpectr R532 perfectly acquires spectrum pigments with high speed and extra quality and refrains from burning of organic compounds widely used in artworks. EnSpectr R532 guarantees non-destructive high level protection of artworks. Instant data at your fingertips: the technology allows to use the instrument with a tablet (or even mount in on the top cover of the instrument), which broadens abilities of a restorer. This type of work is usually done with Raman Microscope of EnSpectr R532 mounted on a sample stage.

3 Measurements 3 Al-Russian Artistic Scientific and Restoration Center named after academician I.E. Grabar Titanium dioxide aureolin (split of painting 0.04mm 2 ) 4 Phthalocyanine manganese blue (split of painting 0.04mm 2 )

4 Parafin & Chalk (split of painting 0.04mm 2 ) National Tretyakovskaya Gallery Ultramarine blue

5 Icon Saint Maxim, XVIII century, National Tretyakovskaya Gallery fund Recognised spectrum from the icon (12mW laser power) Ultramarine dark

6 White lead & Lazurite & Quarzite Chromium oxide

7 Moscow Museum of Modern Art Green acid paint (taken from Surkov s painting) Blue main

8 Paint # 323 Marmeri catalog Paint # 321 Marmeri catalog