Described are the laboratory investigations of components of a late roman opus sectile wall decoration of glass, found in Faiyum. The pieces are compared to similar panels from Kenchreai (Ancient Corinth), wich were almost certainly made in the same place, possibly Egypt. Five separate investigations were undertaken, including chemical analysis and lead isotope analysis of the glasses, identification and radiocarbon dating of the adhesive matrix, and petrographic examination, x-ray diffraction analysis and chemical analysis of the earthenware components. Tables, photographs, sem micrographs.