Types of Gold, Types of Silver: The Composition of Precious Metal Artifacts Found in the Royal Tombs of Ur, Mesopotamia

Abstract

The many gold and silver artifacts from the Early Dynastic Royal Tombs of Ur in Mesopotamia are among the greatest metal finds of Ancient Mesopotamia in the third millennium BC. Within the framework of a research project, 32 of these artifacts were analyzed for their composition using a portable X-ray fluorescence spectrometer and a scanning electron microscope. Predominantly gold-silver alloys rather than pure gold were identified, containing up to 50 wt.% of silver and often with additional copper content well above 10 wt.%. This spectrum of composition ranges from alloys that could be of natural origin to alloys that were intentionally produced. Some gold artifacts were deliberately blended to gold-silver-copper alloys for color gradation. In addition, Sumerian written sources from the end of the third millennium BC can be compared to the results of the analyses of this study and offer more information on the processing of these metals at that time. In the present study, it is shown that gold originating from placer deposits was brought to Ur. Direct association of gold artifacts with lapis lazuli in many precious objects from the Royal Tombs and the particular composition of inclusions of platinum group minerals in the worked gold both point to a possible provenance in northern Afghanistan. One significant result was the confirmation of the use of depletion gilding for the removal of copper from surfaces; the technique of refining silver-bearing gold, known as parting, is not thought to have been known at this time.^[1]

“For the late Hans-Gert Bachmann, the pioneer of ancient gold metallurgy. (Andreas Hauptmann)”