Pseudomorph proposed formation

In 1978, Sibley et al. (7) reported the finding of silk pseudomorphs on three Shang Dynasty bronze weapons at the Museum of Anthropology, University of Missouri-Columbia. The authors considered the work to be preliminary and confirmed a lack of organic structure for the formations adhering to the weapons. By using one of the same weapons as the object for study, Sibley and Jakes (2) proposed microenvironmental conditions necessary for mineralization to occur. Included in that work is a more extensive examination and comparison of published and unpublished reports of the phenomenon than is considered here. The reader is referred to the article for detailed discussion of the earlier studies of pseudomorphs. 

A Proposed Model for the Process of Silk Pseudomorph Formation... 

In order to propose a model for the process of silk fabric pseudomorph formation on the Shang bronze halberd, consideration must be given to... 

Based on a compilation of the preceding information on the probable environment in which the bronze halberd was found, a model can be proposed for the process of silk fabric pseudomorph formation. The presence of an organic material in close proximity to the bronze object alters... 

Pseudomorphs on a bronze Shang Dynasty halberd (ca. 1300 b.c.) were subjected to mineralogical analysis to determine their structure and composition. X-Ray diffraction, scanning electron microscopy, and energy dispersive analysis of x-rays were used in these analyses. Photomicrographs of pseudomorphs also were studied for fiber, yam, and fabric formations that give evidence of textiles. A model describing the process of silk pseudomorph formation was proposed. 

A model for the process of silk pseudomorph formation on bronze is proposed, including solution of copper ions, transport inside the swollen silk, reaction with available anions, and deposition of the resulting products. The maintenance of the outer physical structure of the fiber is attributed to the network of the polymer chains of silk and the maintenance of some structural integrity during degradation. The presence of green and black pseudomorphs of equal size in the same location on the halberd led to a discussion of the possibility of difierential replacement of dyed silk fibers and undyed silk fibers. 

---