LORENZO LAZZARINI

We compiled a database of some of the most important black limestone quarries used in Roman times to be able to determine the provenance of ancient artifacts. For this purpose, we adopted a multimethod approach using the techniques commonly applied to study the provenance of white marbles: petrographic observations, carbon and oxygen isotope composition, electron paramagnetic resonance (EPR) spectra characteristics.

The probable site of extraction and production of Pompeian-style leucite-bearing millstones, singled out by Peacock (1980, 1986) in the vicinity of Orvieto, and the outcropping of the ‘Leucitophyre’ lava have been systematically studied employing standard petrographic and geochemical methods (optical microscopy and ICP–AES/MS spectrometry). The combination of petrochemical data, previously very poor, allowed us definitively to exclude the possible ‘overlap’ of phonolitic and tephri-phonolitic lavas from other Quaternary Volcanic Districts of Latium, and provides a helpful tool for future work on leucitite millstones. Consequently, the databank obtained has been used to attribute the origin of five Roman millstones discovered in three archaeological sites in central Italy (Latium and Marche). It has also been useful to verify the geological provenance of some Sicilian and French leucitite millstones analysed by previous workers. The results point to a provenance from the Orvieto area, with the exception of the millstones from Sicily, for which a different origin was hypothesized.

This contribution presents recent work on an important Roman marble head of the mid-second century ad from the collection of the British Museum (1884,0617.1). The head was found on the Esquiline Hill in Rome in 1884 and soon after its discovery was acquired for the British Museum. Unusually, it retained ex- tensive traces of its original polychromy, including otherwise rarely preserved skin pigments. Ever since the German scholar Georg Treu published the sculpture in 1889, it has played a significant part in the discussion of ancient sculptural polychromy and in particular the question of whether or not the flesh parts of marble sculptures were originally painted. However, early doubts about the authenticity of the pigment traces led some twentieth-century scholars to question the authenticity of the sculpture as a whole.
For this study, the polychromy of the head was extensively investigated using non-invasive techniques (ultraviolet and visible-induced luminescence imaging) and invasive analytical methods, including Raman spectroscopy, Fourier transform infrared spectroscopy, high performance liquid chromatography and gas chromatography-mass spectrometry.
It was found that complex mixtures of pigments, and selected pigments for specific areas, were used to create subtle tonal variations. These included: calcite, red and yellow ochres, carbon black and Egyptian blue for the flesh tones; calcite to provide highlights on the flesh areas; lead white and Egyptian blue for the eyeballs; a red organic colourant in the nostrils, the lachrymal ducts and the inner parts of the mouth; and red and yellow ochre for the hair.
The examination confirmed beyond doubt the authenticity of the preserved pigments and thereby the sculpture itself, which can now rightfully reassume its important place in the art historical discussion of the polychromy of ancient sculpture. In addition, it provided valuable insights into Roman painting techniques on marble and allowed revealing comparisons to be made with other ancient polychrome works, such as funerary portraits.

However, despite the exceptional state of preservation of the colour on the ‘Treu Head’, the small amount of surviving pigment and the extremely complex painting technique do not allow for a satisfactory reconstruction. With the aim of excluding a modern reinterpretation of ancient painting techniques, the colour reconstruction proposed here was created by digitally ‘transplanting’ images of face parts of sculptures and mummy portraits showing paint layers similar to those observed on the ‘Treu Head’. The evidence for the comparison is based on the scientific investigation undertaken on the ‘Treu Head’ and the comparative sculptures and mummy portraits presented in this presentation. The novelty of this colour reconstruction lies not only in the thorough scientific reliability of the data, but also in the use of only Roman painted objects.

The final appearance of the head is therefore not intended as a definitive reconstruction of the ‘original’ appearance of the head, but as a ‘possible’ appearance. In other words, from the scientific evidence the head could have looked like the reconstruction proposed here.


For further information:
G. Verri, T. Opper and T. Deviese, “The ‘Treu Head’: a case study in Roman sculptural
polychromy”, The British Museum Technical Bulletin, 4, 2010 39-54
 
G. Verri, T. Opper and L. Lazzarini, “In picturae modum variata circumlitio?  The reconstruction of the polychromy of a Roman ideal female head (Treu Head)”, in Diversamente Bianco, la policromia della scultura Romana, P. Liverani and U. Santamaria (eds), Edizioni Quasar, Roma 2014 149-183

Lasers for the Cleaning of Statuary: Initial Results and Potentialities L. Lazzarini Laboratorio del Restauro di San Gregorio, Venezia, Italy L. Marchesini Universita di Padova, Padova, Italy JF Asmus Science Applications, Inc., Albuquerque, New Mexico (Received 23 May 1973) ...