Textile fabrics, pseudomorphs evidence

As a form of direct fabric evidence, the physical shapes of textile fabric pseudomorphs have been studied to identify fiber type and yam and fabric construction. Pseudomorphs of paired filaments in mineralized fabric formations found on Shang-period bronze weapons were determined to be replaced silk (I, 2) S-and Z-twisted silk staple yarn pseudomorphs were identified as well as fabric constructions, including float yams and a ribbed weave. 

Little published information exists about textile fabric pseudomorphs. For the most part, those interested in the phenomenon have been concerned with the pseudomorph as textile evidence rather than with the process of its formation. There is no established methodology for examining the pseudomorph either as mineral or as textile. 

Of 101 sampling units drawn, 11 revealed no pseudomorphs after fabrics present, and two points had pseudomorphic evidence that could not be identified because of blurring of the photomicrograph. Only the remaining 88 location points yielded textile information. 

Questions that remain concerning the process of silk fabric pseudomorph formation on the bronze halberd will be resolved with further study of pseudomorphic formations, particularly on objects whose provenance is documented precisely. A more complete description of the microenvironment of the buried objects as well as a quantitative analysis of the mineral composition of the pseudomorphs is necessary for the development of equations for the chemical equilibria involved. Future work is planned to study pseudomorphs as mineralogical structures and pseudomorphs as evidence of textiles. This work includes examination of two additional Shang bronze objects currently on loan to one of the authors. 

Archaeological textiles occasionally occur in forms that mislead the analyst. The mineralized fabric evidence known as pseudomorphs after fabric is one such form. Fabric remains may be recovered in pieces crumpled together and may exhibit pronounced structural variation. In such instances, one cannot rely on a series of tests from one area of the fabric to identify characteristics of the entire fabric. 

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. 

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