Chemical Composition: XRF data from Tracer
Alloy: Bronze
Alloying Elements: copper, tin
Other Elements: lead, iron, arsenic
K. Eremin, January 2014
Chemical Composition: SEM-WDS data from sample, Bronze:
Cu, 89.0; Sn, 10.3; Pb, nd; Zn, 0.06; Fe, 0.29; Ni, nd; Ag, nd; Sb, nd; As, 0.23; Co, nd
Comments: Copper (iron) sulfide inclusions.
R. Newman, June 2015
Technical Observations: The surface is overall covered with a layer of mottled green, blue, and gray-black matte corrosion, which has been worn or flaked off in places to reveal a shiny cupritic brownish-red and silvery-gray metallic surface. The umbo is pierced in the center with a round hole, and the metal is very thin at this point. In other areas, the thin metal has broken off or worn completely through. About one-sixth of the edge is missing. A large, elongated bump corresponds to a scratch and dent on the back, which was created either during excavation or after, as the metal in the scratch is a shiny metallic color.
This object is formed from a thin, hammered sheet of metal. The decorative elements on the wide flange are crudely made by repoussé, using a pointed punch. The central umbo is raised, with a sharp line delineating the transition from the flange. The corrosion layers make it difficult to discern tool marks relating to the basic formation of the object. The edge of the flange is finely finished and slightly thicker; it bears a rope-like pattern that was created using fine diagonal strokes made with a thin flat-ended chisel. On one section of the extant edge, the metal appears to have been hammered too thin, and two flaps of excess metal have been overlaid and both pierced with a corresponding hole, perhaps to hold the edges together. There are three other similarly sized, evenly spaced small holes in the piece that correspond to repoussé dots, but it is unclear whether they were functional or merely a result from wear.
Francesca G. Bewer (submitted 2012)
