Czére Andrea szerk.: A Szépművészeti Múzeum közleményei 102-103. (Budapest, 2005)

MARIANNA DÁGI - MÁRIA TÓTH: A Small Portrait Head of Augustus: Archeometrical Investigations

11 h'RONTAL VIEW OF THF PORTRAIT HEAD OF AUGUSTUS. BUDAPEST. MUSEUM OF FINE ARTS 12 LEFT SIDE OF THE PORTRAIT HEAD OF AUGUSTUS. BUDAPEST. MUSEUM OF FINE ARTS slightly porous (fig. 14). At the broken part of the neck there is a hollow, widening towards the inside of the head, where idiomorphic crystals can be seen (fig. 16). The fracture is not conchoidal (fig. 15). In order to avoid causing visible damage to the head, and to prevent contamination by materials used during previous conservations of the object, a sample representing the whole artefact was taken from inside the head. A tiny splinter, less than 2.5 x 1 x 0.5 mm in size, but considered in its macroscopic appearance to be representative of the object as a whole, was obtained. Sampling was carried out under binocular microscope. In the magnified photo of the splinter, the granular structure of the material is easily visible although slightly out of focus, the depth of field being too low (fig. 17). The characteristic greasy lustre of the surface is noticeable in the picture of the inside of the head taken by the microscope (fig. 15). Crystalline phases were determined by X-ray powder diffraction analysis, and then the sample was subjected to elemental analysis by electron microprobe. The diffraction pattern of the powdered material (fig. 18) shows that the bulk of the material is a-S, crystalline native sulphur in its so-called rhombic modification.