NEW EVIDENCE FOR THE NATURE OF THE ATTIC BLACK GLOSS

New evidence is reported here using transmission electron microscopy, scanning electron microscopy, and laser reflectance for the nature of the black glossy decoration layer present on the Attic black or red fi gure vases of the sixth to fourth century BC. The black layer, of tota l thickness about 20 mum, consists mainly of polycrystalline magnetite (Fe3O4) particles of dimensions from 0.2 mum down to extremely fine s izes embodied in an amorphous vitreous martix. On the outer surface of the black paint we discovered for the first time a thin clear glassy film of approximate thickness 0.1 mum which is rich in Al and Fe and p oor in Si. This film must be responsible for the characterist sheen of the surface. This is verified with the reflection of laser light most ly in specular direction, a unique property compared with black paints of other areas and other periods.