Metals
Over 800 metal artifacts of copper alloy, iron, lead, and silver were excavated from the various strata at Nuzi
and shipped to Harvard. The majority of the metal artifacts are kept at the Semitic Museum.
When these objects arrived at Harvard, they were still obscured by burial accretions and
the effects of corrosion from having been buried for 3,500 years in damp clay soil.
Most of the copper-alloy objects have since been studied.
Most objects made of copper alloys—such as bronze, which is primarily a mixture of copper and tin, or brass,
primarily a mixture of copper and zinc—become disfigured during burial by corrosion pustules that well up through an
object’s surface, gradually transforming it into mineral compounds similar to the ores from which the metal was
originally derived. Depending on their chemical composition, which reacts with the burial environment, some bronzes preserve
their original details by developing enamel-like surfaces. Once excavated, however, a bronze object, whether
beautifully preserved or disfigured, may break out in rapidly spreading, light blue-green, powdery spots.
By the 1930s, it was understood that this was the result of an electrochemical reaction triggered by the effects of
moisture and oxygen on the chloride salts present in the objects.
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