Optical metallography, when complemented by compositional
analysis, can reveal in some detail the various kinds of treatment that a metal artifact has
experienced during its manufacture, and suggest what practical properties it might be expected
to have, such as strength against fracture or an ability to take a keen edge. Groups of artifacts
from excavated contexts then can be used to pinpoint crucial moments of change in metalworking
traditions, while intra-and inter-regional comparisons of technological styles can enhance our
understanding of metals, both mundane and precious, in their social context.
At the Penn Museum, we have specialized in the copper-to-bronze transition in Old World metallurgy-particularly
how that transition played out in early Mesopotamia and Thailand-and in the development of copper,
iron, and gold metallurgy of the New World, the latter studies focusing of the exquisite items
recovered during the Museum's excavations at Sitio Conte, in Panama.
Left: Copper spear-point
(As, 3.0%; Sn, <0.016%; Ni, 4.8%)
Ur, private grave 1733
ED III (circa 2150–2000 B.C.)
Photograph: Lindsay Shafer, MASCA