Chemical Composition: ICP-MS/AAA data from sample, Bronze:
Cu, 91.61; Sn, 7.86; Pb, 0.09; Zn, 0.013; Fe, 0.09; Ni, 0.02; Ag, 0.03; Sb, 0.04; As, 0.25; Bi, less than 0.025; Co, less than 0.005; Au, less than 0.01; Cd, less than 0.001
Chemical Composition: XRF data from Tracer
Alloying Elements: copper, tin
Other Elements: lead, iron, arsenic
K. Eremin, January 2014
Chemical Composition: EMP analysis from sample, Bronze:
Cu, 90.68; Sn, 8.02; Pb, 0.05; Zn, 0.00; Fe, 0.08; Ni, 0.01; Ag, 0.02; Sb, 0.01; As, 0.12
M. McNamara, October 2000
Technical Observations: The helmet is in a good condition. There is a small loss from the bottom front edge of the proper left cheek guard. The exterior of the top has been abraded, possibly as part of a restoration. There are small fills and repairs on the surface.
The helmet was made from one piece of metal. X-radiographs show long narrow hammer marks in a semicircular pattern. X-radiographs also demonstrate that the hole on the intact cheek guard was punched, as the edges are dense and curve inward. The front edges of the cheek guards are heavily mineralized. There is no evidence of porosity, gates, risers, or chaplets from casting. A spotted pale green patina with thicker areas of blue colored corrosion covers the interior surfaces. The interior of the proper right cheek has a pseudomorph resembling a matted down, fibrous material. While this could be from a lining material, it resembles human hair more.
Metallographic examination of the helmet reveals intergranular corrosion that confirms the metal is ancient. Extensive deformation lines and both straight and bent annealing twins indicate numerous cycles of hammering and annealing. Compressed and elongated grains and inclusions indicate that the ridge along the bottom edge of the helmet was formed by upsetting, that is, it was hammered back into itself. There is no evidence of coring, a dendritic structure, or porosity, all of which are microstructural features consistent with casting. The thickness of the metal varies from 0.1 to 1.9 cm.
Molly McNamara (submitted 2000)